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Monday, December 31, 2007

AMD's Athlon 64 X2 3800+ processor

AMD's Athlon 64 X2 3800+ processor
Let the upgrades begin
by Scott Wasson — 2:26 AM on August 1, 2005 for THE TECH REPORT

WHEN WE FIRST reviewed the Athlon 64 X2 processor a few months back, we said that it was an outstanding CPU, but we wished out loud for AMD to start selling a 2GHz version of the X2 at a lower price. After all, we argued, Intel's Pentium D 820 is a killer deal at just under $250, while the least expensive Athlon 64 X2 costs over twice that. Sure, the X2's performance might well justify the price premium, but we'll take more for our money when we can get it.

Today, our wish is fulfilled in the form of the Athlon 64 X2 3800+, a dual-core processor running at 2GHz with 512K of L2 cache per core. AMD has priced this baby at $354—significantly less than any of its other dual-core products. It doesn't take a Ph.D. in computer engineering to figure out that the X2 3800+ ought to offer a very potent combo of price and performance.

As is our custom, we compared the X2 3800+ against over a dozen single- and dual-core competitors to see just how it fits into the big picture. Then we overclocked the living daylights out of the thing, and everything went soft and fuzzy. Our heads are still spinning. Keep reading to see why.

Code name: Manchester
Our first exposure to the Athlon 64 X2 came in the form of the 4800+ model. That chip is code-named "Toledo," and it packs 1MB of L2 cache per processor core, as do the dual-core Opterons. Toledo-core chips sport a transistor count of about 230 million, all crammed into a die size of 199 mm2.

AMD also makes several models of Athlon 64 X2 that have only 512K of L2 cache. In the past, CPUs with smaller caches have sometimes been based on the exact same chip as the ones with more cache, but they'd have half of the L2 cache disabled for one reason or another. That's not the case with the X2 3800+. AMD says this "Manchester"-core part has about 154 million transistors and a die size of 147 mm2, so it's clearly a different chip. AMD rates the max thermal power needed to cool the X2 3800+ at 89W—well below the 110W rating of the 4800+—and they've revised down the max thermal power of the X2 4200+ to 89W, as well. The Manchester core is obviously a smaller, cooler, and cheaper-to-manufacture chip than Toledo.


The Athlon 64 X2 3800+ Cosmetically, though, you'd never know it, because the X2 3800+ looks like pretty much any other Socket 939 processor. The X2 3800+ is intended to work with AMD's existing Socket 939 infrastructure, and it may well be an upgrade option for current owners of Athlon 64 systems. You'll want to check with your motherboard maker to see whether or not your board will support an X2 before making the leap, though. Some boards need only a BIOS update, but we're finding out that some others just can't handle X2 processors. Most newer motherboards should be fine.

Before we dive into the benchmark numbers, let's have a quick look at where the X2 3800+ fits into the bigger picture. With its introduction, the Athlon 64 X2 family now looks like so:

CPU Clock speed L2 cache size Price
Athlon 64 X2 3800+ 2.0GHz 512KB $354
Athlon 64 X2 4200+ 2.2GHz 512KB $482
Athlon 64 X2 4400+ 2.2GHz 1024KB $537
Athlon 64 X2 4600+ 2.4GHz 512KB $704
Athlon 64 X2 4800+ 2.4GHz 1024KB $902

At $354, the X2 3800+ isn't exactly cheap, but it does extend the X2 line into more affordable territory. You've probably noticed the apparent hole in the X2 models at 4000+. Logic would dictate that the X2 4000+ would run at 2GHz and have 1MB of L2 cache. So where is it? I asked AMD this very question, and they told me that they won't comment on unannounced products—and besides there aren't any plans for an X2 4000+ right now.

I'm not too broken up about that, because I'm not convinced the additional L2 cache is worth paying more money to get. We'll address that issue in more detail when we look at the benchmark results.

Now for something really confusing. How does the Athlon 64 X2 3800+ stack up against the competition? Figuring out such things has become horribly puzzling as Model Number Mania has taken hold of the CPU market. Here's my attempt at lining up the various AMD and Intel CPU models according to rough price parity:

CPU Price CPU Price CPU Price CPU Price CPU Price
Pentium 4 541 $218 Pentium 4 630 $224

Athlon 64 3200+ $194

Pentium 4 551 $278 Pentium 4 640 $237 Pentium D 820 $241 Athlon 64 3500+ $223





Pentium D 830 $316 Athlon 64 3800+ $329 Athlon 64 X2 3800+ $354
Pentium 4 561 $417 Pentium 4 650 $401

Athlon 64 4000+ $375









Athlon 64 X2 4200+ $482




Pentium D 840 $530

Athlon 64 X2 4400+ $537
Pentium 4 571 $637 Pentium 4 660 $605



Athlon 64 X2 4600+ $704


Pentium 4 670 $851

Athlon 64 FX-55 $827



Pentium 4 XE 3.73GHz $999 Pentium XE 840 $999 Athlon 64 FX-57 $1031 Athlon 64 X2 4800+ $902

From this handy table, we learn that the X2 3800+'s dual-core competition from Intel is probably the Pentium D 830. You can have a single-core Pentium 4 551 for about 75 bucks less than the price of the X2 3800+, or you could pick up AMD's single-core Athlon 64 3800+ in the same basic price range as the "equivalent" X2. The Athlon 64 3800+ runs at 2.4GHz and has a 512K L2 cache, so you lose 400MHz and pick up a whole second CPU core by going for the X2 3800+ instead. I'd say that's an easy tradeoff to make, but the benchmark results will tell us more about the shape of that choice.

AMD's dual-core Opteron processors

AMD's dual-core Opteron processors
Because four is better than two
by Scott Wasson — 5:16 AM on April 21, 2005 for THE TECH REPORT

MICROPROCESSORS ARE GETTING too hot, requiring too much power, and not delivering enough additional performance for it. That's the basic problem. The engine that's driven the microcomputer's incredible rise in capability over the past 30 years, Moore's Law, isn't quite out of steam yet, but some of its offshoots are on the ropes. CPU designers have nearly exhausted their collective bag of tricks to get more performance out of additional transistors on a chip by increasing parallelism at the instruction level. Speculative execution and deep pipelining are by now very standard features, and CPU designs are getting increasingly complex and hard to manage. When Gordon Moore's goose lays a golden egg and the number of transistors possible on a chip doubles, as it is supposed to do every 18 months, taking advantage of the windfall has proven increasingly difficult.

Cranking up clock speeds hasn't helped much, either, because of transistor leakage problems. Chips are sucking up large amounts of power and expending much of it as heat, and the problem grows more acute as clock speeds ramp up. The most widely noted example of these problems, by far, has been at the company Moore co-founded. The power, heat, and speed problems of the "Prescott" core inside of recent Pentium 4 processors prompted Intel into an impressive and very public change of direction over the course of the past year. The company has sworn off the quest for 4GHz, shied away from clock speed as a measure of performance, and utterly rewritten its CPU roadmap.

AMD has not been entirely immune to these problems, but it has sidestepped their worst effects by keeping clock speeds down. The original Opteron processor debuted two years ago today at speeds up to 2GHz. Two years later, the same processors are available at 2.6GHz—only a 600MHz increase, not much in the grand scheme.

Fortunately, both AMD and Intel seem to have settled on an answer that should allow them to take advantage of ballooning transistor counts to gain additional performance: thread-level parallelism. By dialing back clock speeds and putting multiple CPU cores on a chip, the theory goes, processor performance can rise as transistor counts do. This sort of parallelism will, of course, be familiar to those who know a thing or two about Opteron processors, which have commonly been employed in pairs as part of server or workstation systems.

In fact, AMD says that the Opteron was designed from the outset with dual-core implementations in mind. The folks there are also quick to remind anyone who will listen that AMD was first to tape out an x86-compatible dual-core design and first to demonstrate such a beast in public. Today, they aim to be the first manufacturer to deliver dual-core x86 processors for workstations and servers, just days after Intel officially announced its first dual-core desktop processors.

We've had a pair of dual-core Opteron processors on the test bench for some time now, and we're pleased to report some rather impressive results. AMD's dual-core design is something more than just a pair of CPUs glued together on a single piece of silicon, and this design choice yields a performance dividend. Keep reading to see how the new Opteron 275 stacks up against its Opteron predecessors and against Intel's latest "Nocona" Xeons. We also have a head-to-head battle of single-socket, dual-core workstation processors: the Opteron 175 versus the Pentium Extreme Edition 840.

The processors
On looks alone, one would be hard pressed to tell the difference between dual-core Opterons and their single-core counterparts.

They're cosmetically identical, save for the slightly revamped model numbering scheme. The three-tiered processor series convention remains intact. 100 series processors are for single-socket systems, the 200 series for dual, and the 800 series is intended for 4-socket systems or better. However, instead of incrementing the tail end of the model number by two as clock speeds ramp up, as the Opterons 246, 248, and 250 did, the dual-core models will come in increments of five. The first dual-core Opterons will arrive at clock speeds of 1.8, 2.0, and 2.2GHz as models x65, x70, and x75, respectively.

Prices will vary according to whether the chips are part of the 100, 200, or 800 series and according to clock speeds, but the general plan for pricing is fairly straightforward: it's almost as if AMD were introducing three new top-end speed grades at once. However, there is some overlap. For instance, the Opteron 252 is priced at $851, and the Opteron 265 will be priced the same. Consumers can choose whether they wish to purchase a dual-core processor at 1.8GHz or a single core at 2.6GHz for the same amount. The higher models will carry a premium, but AMD plans to bring the prices of dual-core Opterons down over time into the territory of the current single-core models.

The even better news for current owners of Opteron systems is that the dual-core Opterons will be pin-compatible with existing Socket 940 systems, capable of acting as drop-in replacements for current single-core models. The only requirement is that the motherboard must be able to support newer 90nm chips like the Opteron 252. If the board can do that, it should be able to handle the dual-core chips after a BIOS update, AMD claims. (Check with your motherboard maker to be sure.)

In order to pull off this impressive feat of backward compatibility, AMD had to make its dual-core parts fit into the same basic power and heat envelopes as its single-core processors. To do so, the company tweaked its fabrication process, using lower-leakage transistors that switch somewhat slower but waste less power, among other things. As a result, the Opteron 275 tops out at 2.2GHz, but it consumes no more power than the Opteron 252 at 2.6GHz.

This is one of the minor miracles of choosing thread-level parallelism over higher clock speeds. When we asked AMD CTO Fred Weber about how they managed to keep power and heat so low, he was coy about which specific optimizations AMD employed, but he offered some examples. When you're not optimizing for the absolute best linear performance, he noted, many things are possible, including everything from changing the oxide thickness and transistor voltages to resizing buffers and more extensive clock gating.

To further manage heat and power, dual-core Opterons will support AMD's PowerNow feature (also known as Cool'n'Quiet in the desktop world) that scales clock speeds and CPU voltages down at times of low CPU loads. This feature will function on a whole-chip basis; the CPU cores will not scale their clock speeds up and down independently.

As for the chip itself, the dual-core Opteron will be manufactured on AMD's 90nm process with silicon-on-insulator (SOI) technology. The chips will include all of the latest enhancements AMD has made to the K8 core, including SSE3 support and an improved memory controller with broader compatibility, improved memory loading, and more efficient memory mapping.

A dual-core Opteron chip packs in about 233 million transistors, and its die size is a very healthy 199 mm2. The Intel Prescott/Nocona on which the Xeon is based is 112 mm2 with roughly 125 million transistors. (The newer version with 2MB of L2 cache has 133 million transistors.) So the dual-core Opteron is large, but it's also a very close match for Intel's "Smithfield" dual core, which weighs in at roughly 230 million transistors and 206 mm2, although estimates and methods of counting transistors can vary.

Sunday, December 23, 2007

RSS - Rich Site Summary


Or Really simple syndication. Whichever it is, the concept is really novel and useful for the average internet using public.But more than three-quarters of the experienced or amateur surfing population doesn't know WHAT it is and how useful this is.The ignorance levels are appalling that when we had decided on a mini project ,a simple "Desktop Feed Aggregator/Reader" many of them sat with a gaping mouth and bulging eyeballs.So what is this RSS ?and how is it useful ? Here I am going to touch upon RSS and how to go about making your own feeds.

WIKIPEDIA
says
RSS (formally "RDF Site Summary", known colloquially as "Really Simple Syndication") is a family of webfeeds formats used to publish frequently updated content such as blog entries, news headlines or podcasts. An RSS document, which is called a "feed", "web feed", or "channel", contains either a summary of content from an associated web site or the full text. RSS makes it possible for people to keep up with their favorite web sites in an automated manner that's easier than checking them manually.

Thats it! You can check for updates using a feed reader rather than going to a site.Imagine checking your college site for any updates,every hour. Subscribing to a feed is really simple if you are using FireFox.It has a simple enough RSS Reader thats inbuilt.Whenever you visit a site that's syndicated,a
bright orange tab can be seen at the right end of the address bar.Click on it, and choose your preferred reader.

Building personal RSS feed,
step by step

At start, this is just a simple text file, created with any text
editor. But an XML editor is more convenient. The name may be, for example: "feed.xml".
The overall structure is as that:




<?xml version="1.0" ?>

<rss version="2.0">

<channel>



</channel>

</rss>



1) Define the source, by the channel tag

The channel will be the same for all your RSS feeds. These tags
are required:
- title: the title of your website, may be the one in the
title tag of the home page.
- link: the URL of your website: example: http://www.xul.fr
- description: description of your website, about 200 characters,
this may be the text assigned to the content attribute of the
description tag, in the head section of the home page.








<channel>

<title>XUL
and XML</title>

<link>http://www.xul.fr/</link>


<description>Xml
graphical interface etc...</description>

</channel>



2) Add an image

This is optional. Design a small image (88x31 for example) in a common format
(gif, jpg, png) and put in into the same directory that the RSS file.
The "image" tag is a sub-element of the channel tag
- url is the address of the image itself.
- link is the address of the page displayed when one clicks on the
image.






<channel>
<title> </title>
<link> </link>
<image>
<url>http://www.xul.fr/xul.gif</url>
<link>http://www.xul.fr/index.html</link>
</image>
</channel>

3) Add a new item

Now, we will add a web page to display an information. This is
an "item" tag, a sub-element of channel, and this components
are required:
- title: the title of the article.
- link: the URL of the page.
- description: a summary of the article, about 200 characters.







<item>
<title>News of today</title>
<link>http://www.xul.fr/xml-rss.html</link>
<description>All you need to
know about RSS</description>
</item>

4) Add more items

More items may be added to this channel.

5) Upload the file

Put the feed.xml file into your website, among other web pages.

6) Validate the file

You may use this online RSS
feed validator
.


7) Make it available

This is accomplished by adding an RSS button on the home page. A click on

the button should display the XML file you have created.







<a href="http://www.xul.fr/feed.xml>
<img src="rss.gif"> </a>


If the image is not displayed, use a complete URL, as http://www.xul.fr/rss.gif,
for example.

8) Updating the feed

To publish further articles, you have just to add items, and
remove older ones to keep the number of articles constant.

Saturday, December 22, 2007

Passwords . A New Perspective

Text in itallics represent my views. The rest are quoted.

This article refers only to those Passwords that are used to login into online systems like email accounts, or services.Having been introduced to the backend and frontend of the virtual world simultaneously has helped me to gain that special insight into the working of the internet.Although i dont profess to be much of an expert to offer advice,i feel qualified enough to assess the present situation in these areas and write upon it.
A basic Login authentication system contains a database that keeps the information that users sub
mit upon registration.i.e your passwords are indeed stored somewhere and can be seen by the system administrator.Most decent web service providers (eg: yahoo , gmail ... amazon...) do not store the passwords in plain text form rather they are encrypted.A simple one way encryption algorithm , that i have used is MD5.Its too big to write in one blog.Maybe I'll write upon MD5 and methods to decrypt in another post.maybe...
That they are encrypted , is the reason why you can never ask the providers to give you the password.On
e can only reset it.
So the point is , all information that is submitted is stored and is viewable by a human.
Whenever a user requests access to a login secured page, the password that is provided along with the username is checked with the ones in database and if it matches, the user is logged in.Basic hack attempt starts here.

Passwords Reveal Your Personality
A spontaneously-generated password may be more revealingthan you think.
The random catchphrase that accesses your e-mail account may unlock your psyche as well as your correspondence, say experts..
The study identified four password "genres." "Family-oriented" respondents numbered nearly half of those surveyed. These people select their own name or nickname, the name of a child, partner or pet, or a birth date. They tend to be occasional computer users and have strong family ties. "They choose passwords that symbolize people or events with emotional value," Indeed. One third of respondents were "fans," using the names of athletes, singers, movie stars, fictional characters or sports teams. Fans are young and want to ally themselves with the lifestyle represented by a celebrity. Two of the most popular names were Madonna and Homer Simpson. Eleven percent of responses were from "fantasists." Their interest in sex is evident in passwords such as "sexy," "stud" and "goddess." "Traditionally, these individuals are male, but 37 percent of fantasists identified themselves as female," . The final ten percent of participants are "cryptics," because they pick unintelligible passwords or a random string of letters, numerals and symbols, such as Jxa+157. Petrie says cryptics are the most security-conscious group. They tend to make the safest but least interesting choices.

Passwords are inadvertently revealing for two reasons. First, they are generated on the spot. "Since you're focused on getting into the system, you're likely to put down something that comes readily to mind," . "In this sense, passwords tap into things that are just below the surface of consciousness, much the way Rorschach and word-association tests do. Also, to remember your password you pick something that will stick in your mind. You may unconsciously choose something of particular emotional significance."

I personally vouch for all the four genres, i have seen people using all of the above mentioned four.
Additionally there's one more group of people who belongs to the category "stupid"
for the zillions who use "Trustno1", "Swordfish", "Password","qwerty","123456","abc123"..... the only reason they're ever considered passwords are ,because they're 6 letters long.

Password psychology is a field of cryptography and psychology that studies how passwords are chosen and what determines users to choose a certain password. The discipline reveals several details about the way users remember and choose passwords, allowing system administrators to improve the safety of the passwords

Basic studies

It has been demonstrated that users usually remember passwords by associating them with something. This is done either mnemonically, where users associate letters and numbers with a certain meaning, or mechanically, learning the password by heart but associating it with a certain movement of their fingers on the keyboard. For example, a Pink Floyd fan may remember gbBs2u as "good bye Blue sky to you" (close to the lyrics of a Pink Floyd song). Other users may have no other alternative than learning the password by heart. However, it will be more difficult for them to remember it when using a different keyboard map, even when the keyboard map is only slightly different (for example, Eastern keyboard maps often interchange the location of the Y and Z keys on Western keyboard maps).

These studies were a stepping stone in discovering several yet unknown facts about password choices, allowing some cryptographic schemes to be developed separately, especially for people with disabilities, for example.

But the fact remains.The average internet users are dumb.And the remaining ones,well, they aren't




Wednesday, December 12, 2007

VI - Some useful commands

  • a enter insert mode, the characters typed in will be inserted after the current cursor position.
  • h move the cursor to the left one character position.
  • i enter insert mode, the characters typed in will be inserted before the current cursor position.
  • j move the cursor down one line.
  • k move the cursor up one line.
  • l move the cursor to the right one character position.
  • r replace one character under the cursor. Specify count to replace a number of characters
  • u undo the last change to the file. Typing u again will re-do the change.
  • x delete character under the cursor.
  • yy yank until , putting the result into a buffer. "yy" yanks the current line. a count yanks that many lines. The buffer can be specified with the " command. If no buffer is specified, then the general buffer is used.
  • p paste
  • o Enter insert mode in a new line below the current cursor position.
  • % Move the cursor to the matching parenthesis or brace.
  • / Search the file downwards for the string specified after the /
  • ? Search the file upwards for the string specified after the ?.
  • ~ Switch the case of the character under the cursor.
  • R Replace characters on the screen with a set of characters entered, ending with the Escape key.
  • S Change an entire line.

My browser crashed atleast three times while writing this blog! That's VI

Thursday, December 6, 2007

All about Linux swap space

By Gary Sims on December 03, 2007 at Linux.com

When your computer needs to run programs that are bigger than your available physical memory, most modern operating systems use a technique called swapping, in which chunks of memory are temporarily stored on the hard disk while other data is moved into physical memory space. Here are some techniques that may help you better manage swapping on Linux systems and get the best performance from the Linux swapping subsystem.

Linux divides its physical RAM (random access memory) into chucks of memory called pages. Swapping is the process whereby a page of memory is copied to the preconfigured space on the hard disk, called swap space, to free up that page of memory. The combined sizes of the physical memory and the swap space is the amount of virtual memory available.

Swapping is necessary for two important reasons. First, when the system requires more memory than is physically available, the kernel swaps out less used pages and gives memory to the current application (process) that needs the memory immediately. Second, a significant number of the pages used by an application during its startup phase may only be used for initialization and then never used again. The system can swap out those pages and free the memory for other applications or even for the disk cache.

However, swapping does have a downside. Compared to memory, disks are very slow. Memory speeds can be measured in nanoseconds, while disks are measured in milliseconds, so accessing the disk can be tens of thousands times slower than accessing physical memory. The more swapping that occurs, the slower your system will be. Sometimes excessive swapping or thrashing occurs where a page is swapped out and then very soon swapped in and then swapped out again and so on. In such situations the system is struggling to find free memory and keep applications running at the same time. In this case only adding more RAM will help.

Linux has two forms of swap space: the swap partition and the swap file. The swap partition is an independent section of the hard disk used solely for swapping; no other files can reside there. The swap file is a special file in the filesystem that resides amongst your system and data files.

To see what swap space you have, use the command swapon -s. The output will look something like this:

Filename        Type            Size    Used    Priority
/dev/sda5 partition 859436 0 -1

Each line lists a separate swap space being used by the system. Here, the 'Type' field indicates that this swap space is a partition rather than a file, and from 'Filename' we see that it is on the disk sda5. The 'Size' is listed in kilobytes, and the 'Used' field tells us how many kilobytes of swap space has been used (in this case none). 'Priority' tells Linux which swap space to use first. One great thing about the Linux swapping subsystem is that if you mount two (or more) swap spaces (preferably on two different devices) with the same priority, Linux will interleave its swapping activity between them, which can greatly increase swapping performance.

To add an extra swap partition to your system, you first need to prepare it. Step one is to ensure that the partition is marked as a swap partition and step two is to make the swap filesystem. To check that the partition is marked for swap, run as root:

fdisk -l /dev/hdb

Replace /dev/hdb with the device of the hard disk on your system with the swap partition on it. You should see output that looks like this:

 Device Boot    Start   End     Blocks  Id      System
/dev/hdb1 2328 2434 859446 82 Linux swap / Solaris

If the partition isn't marked as swap you will need to alter it by running fdisk and using the 't' menu option. Be careful when working with partitions -- you don't want to delete important partitions by mistake or change the id of your system partition to swap by mistake. All data on a swap partition will be lost, so double-check every change you make. Also note that Solaris uses the same ID as Linux swap space for its partitions, so be careful not to kill your Solaris partitions by mistake.

Once a partition is marked as swap, you need to prepare it using the mkswap (make swap) command as root:

mkswap /dev/hdb1

If you see no errors, your swap space is ready to use. To activate it immediately, type:

swapon /dev/hdb1

You can verify that it is being used by running swapon -s. To mount the swap space automatically at boot time, you must add an entry to the /etc/fstab file, which contains a list of filesystems and swap spaces that need to be mounted at boot up. The format of each line is:

                           

Since swap space is a special type of filesystem, many of these parameters aren't applicable. For swap space, add:

/dev/hdb1       none    swap    sw      0       0

where /dev/hdb1 is the swap partition. It doesn't have a specific mount point, hence none. It is of type swap with options of sw, and the last two parameters aren't used so they are entered as 0.

To check that your swap space is being automatically mounted without having to reboot, you can run the swapoff -a command (which turns off all swap spaces) and then swapon -a (which mounts all swap spaces listed in the /etc/fstab file) and then check it with swapon -s.

Swap file

As well as the swap partition, Linux also supports a swap file that you can create, prepare, and mount in a fashion similar to that of a swap partition. The advantage of swap files is that you don't need to find an empty partition or repartition a disk to add additional swap space.

To create a swap file, use the dd command to create an empty file. To create a 1GB file, type:

dd if=/dev/zero of=/swapfile bs=1024 count=1048576

/swapfile is the name of the swap file, and the count of 1048576 is the size in kilobytes (i.e. 1GB).

Prepare the swap file using mkswap just as you would a partition, but this time use the name of the swap file:

mkswap /swapfile

And similarly, mount it using the swapon command: swapon /swapfile.

The /etc/fstab entry for a swap file would look like this:

/swapfile       none    swap    sw      0       0

How big should my swap space be?

It is possible to run a Linux system without a swap space, and the system will run well if you have a large amount of memory -- but if you run out of physical memory then the system will crash, as it has nothing else it can do, so it is advisable to have a swap space, especially since disk space is relatively cheap.

The key question is how much? Older versions of Unix-type operating systems (such as Sun OS and Ultrix) demanded a swap space of two to three times that of physical memory. Modern implementations (such as Linux) don't require that much, but they can use it if you configure it. A rule of thumb is as follows: 1) for a desktop system, use a swap space of double system memory, as it will allow you to run a large number of applications (many of which may will be idle and easily swapped), making more RAM available for the active applications; 2) for a server, have a smaller amount of swap available (say half of physical memory) so that you have some flexibility for swapping when needed, but monitor the amount of swap space used and upgrade your RAM if necessary; 3) for older desktop machines (with say only 128MB), use as much swap space as you can spare, even up to 1GB.

The Linux 2.6 kernel added a new kernel parameter called swappiness to let administrators tweak the way Linux swaps. It is a number from 0 to 100. In essence, higher values lead to more pages being swapped, and lower values lead to more applications being kept in memory, even if they are idle. Kernel maintainer Andrew Morton has said that he runs his desktop machines with a swappiness of 100, stating that "My point is that decreasing the tendency of the kernel to swap stuff out is wrong. You really don't want hundreds of megabytes of BloatyApp's untouched memory floating about in the machine. Get it out on the disk, use the memory for something useful."

One downside to Morton's idea is that if memory is swapped out too quickly then application response time drops, because when the application's window is clicked the system has to swap the application back into memory, which will make it feel slow.

The default value for swappiness is 60. You can alter it temporarily (until you next reboot) by typing as root:

echo 50 > /proc/sys/vm/swappiness
If you want to alter it permanently then you need to change the vm.swappiness parameter in the /etc/sysctl.conf file

Conclusion

Managing swap space is an essential aspect of system administration. With good planning and proper use swapping can provide many benefits. Don't be afraid to experiment, and always monitor your system to ensure you are getting the results you need.

Sunday, December 2, 2007

Classic Sherlock Holmes Quotes



  • My name is Sherlock Holmes. It is my business to know what other people don't know." ("The Adventure of the Blue Carbuncle")

  • "My brain has always governed my heart." ("The Sign of Four")

  • "Love is an emotional thing, and whatever is emotional is opposed to that true cold reason which I place above all things. I should never marry myself, lest I bias my judgment." ("The Sign of Four")

  • "A man always finds it hard to realize that he may have finally lost a woman's love, however badly he may have treated her." ("The Musgrave Ritual")
  • "There is nothing more deceptive than an obvious fact." ("The Boscombe Valley Mystery")

  • "You can...never foretell what any one man will do, but you can say with precision what an average number will be up to. Individuals vary, but percentages remain constant." ("The Sign of Four")

  • "Education never ends, Watson. It is a series of lessons, with the greatest for the last." ("The Adventure of the Red Circle")

  • "When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth." ("The Adventure of The Blanched Soldier")

  • "I never make exceptions. An exception disproves the rule." ("The Sign of Four")
“you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.” (A Study in Scarlet)

Friday, November 16, 2007

Eight most Essential FireFox Extensions(revisited)

Since the post in March 2007 [link], many a people have commented that as a good review of extensions.
As an add on, here are those extensions, plus two more , along with their current ratings and a downoad link, since that was a long standing demand.
For IE-6 users , its high time you see the web through Firefox and feel the difference.

  • BugMeNotBypass compulsory web registration with www.bugmenot.com
[i don't use it any more.Long since i started knocking the right doors and totally ignoring the obscure ones.I don't wander around the labyrinth of websites anymore.]
  • Del.icio.uskeep , share and discover all your favourite things Most well used.
The delicious top ten rocks... Comes up with a classic new site bookmarked by real people in every 1 or 2 hour or so.
  • FlashblockReplaces flash objects with a button you can click to view them
Still rocks.... I use it everyday without even giving it a thought.A word of caution:you'll be missing the google home page for a long time if you start using this :P
  • IE tab
Obsolete
  • Scrapbook Helps you to save web pages and organize the collection
AS ever faithful thy serve...
  • Webdeveloper Adds a menu and a Toolbar with various webdeveloper tools
Occasionlly useful.Serious web-developing tool.
  • Febe - Firefox Extensions Backup Extension
Well... How could have i come with this post with download links , but for this ever faithful fellow? FEBE now provides a complete profile backup!! Cool. The implication is that your scrapbook pages,bookmarks are all backed up . AMAZING

[FEBE interface, reduced for sake of readability]----------->

The New Look


Sarathainside takes a new look on the world as of today.

Tuesday, November 13, 2007

euphoria over Euphoria . cool








maeri video.I really like the visuals.Amazing work .

Wednesday, November 7, 2007

Once in a blue moon



"once in a blue moon,
maybe in a monsoon,
just after noon,
it would be a boon,

to talk to you by a lagoon

like a goon,
and i hope that happens real soon"





Idioms are phrases and sentences that do not mean exactly what they say. Even if you know the meaning of every word in the see or hear, you may not understand the idiom because you don't understand the culture behind it.


Monday, October 22, 2007

The (re)Union

Three days ago,when finally after 2 1/2 years, our alumni meet which was supposedly never supposed to happen, took place, i feel contended. Somehow ,against all precedences to the contrary , i managed to do the right things, at the right time.Which is a lot, given the long history of inaction that i have been accustomed to.

Saturday, October 6, 2007

The IGNobels.

The Ig Nobel Prizes are a parody of the Nobel Prizes and are given each year in early October — around the time the recipients of the genuine Nobel Prizes are announced — for ten achievements that "first make people laugh, and then make them think." Organized by the scientific humor magazine Annals of Improbable Research (AIR), they are presented by a group that includes genuine Nobel Laureates at a ceremony at Harvard University's Sanders Theater.

The Ig nobels, recognise the fun aspect of serious research.It brings in a human moment to geeks immersed in saving mankind.I am wondering why this hasn't become the talk of the world, I am sorry if it is , but that's not the case in my part of the world. Most of them haven't even heard of it.

Here , i am listing down the most outrageous of them along with this year's recipients.

2007

  • Aviation: Patricia V. Agostino, Santiago A. Plano and Diego A. Golombek, for discovering that hamsters recover from jetlag more quickly when given Viagra.
  • Biology: Johanna E.M.H. van Bronswijk, for taking a census of all the mites and other life forms that live in people's beds.
  • Chemistry: Mayu Yamamoto for extracting vanilla flavor from cow dung.
  • Economics: Kuo Cheng Hsieh, for patenting a device to catch bank robbers by ensnaring them in a net.[3]
  • Linguistics: Juan Manuel Toro, Josep B. Trobalon and Nuria Sebastian-Galles, for determining that rats sometimes can't distinguish between Japanese, played backward, and Dutch, played backward.
  • Literature: Glenda Browne, for her study of the word "the". [4]
  • Medicine: Dan Meyer and Brian Witcombe, for investigating the side-effects of swallowing swords.
  • Nutrition: Brian Wansink, for investigating people's appetites by secretly feeding them a self-refilling bowl of soup.
  • Peace: The Air Force Wright Laboratory in Dayton, Ohio, for research and development of a "gay bomb," which would cause enemy troops to become sexually attracted to each other.
  • Physics: L. Mahadevan and Enrique Cerda Villablanca for their theoretical study of how sheets become wrinkled.
gosh.. come to think of it. Everything's outrageously outrageous. It would fill in 10s of pages. I would like to mention about one that's from my own place . Awarded in 2002 in

Mathematics - Presented to K.P. Sreekumar and G. Nirmalan of Kerala Agricultural University, India, for their analytical report "Estimation of the Total Surface Area in Indian Elephants."
Incredible !!! ain't it? awesome .

The ignobels draw attention to scientific articles that have some humorous or unexpected aspect. Examples range from the discovery that the presence of humans tends to sexually arouse ostriches, to the statement that black holes fulfill all the technical requirements to be the location of Hell, to research on the "five-second rule," a tongue-in-cheek belief that food dropped on the floor won't become contaminated if it is picked up within five seconds.

Got inspired? let me know. And why don't you check out
other mock awards:




(sourced from the one and only wikipedia)

Everything you do can be traced back to you!

Posted on gadgetell.com, July 24th, 2007 at 9:52 AM by Robert Nelson

Section: News

harry potter and the deathly hallowsHarry Potter fans all over could not wait to get their hands on the latest release but someone just could not control their excitement and took some time to photograph each and every page and then made them available via BitTorrent before the books actual release. For some people this may have seemed like a wonderful and quick way to find out just how the final Harry Potter book will end however it could really be the end for the person who posted the pictures.

The EFF checked out the leaked pictures and did some investigating of their own. They found that the EXIF metadata contained the serial number of the camera along with some information about the settings. The camera in question was a Canon Rebel 300D. With a unique serial number it is possible to find the person who took the images. Of course it would still not be a perfect or easy quest. The camera would have to have been registered when first purchased and even then it could have been registered with old or inaccurate information.

So while it would be hard to track down the owner of that camera it just brings a good point, in today’s digital age it is becoming very hard to stay anonymous. In the past we have seen information tracked by hidden details left from laser printers, Word documents, PDF files, CD burners and software. While I am not a fan of this hidden information its also not a huge concern for me because I am not someone who would leak something like this. So leakers be warned, you most likely can be tracked.

Thursday, September 13, 2007

"What do you do? What do you do?"














Its hard to imagine the sources of inspiration. I was just watching tv one day and saw this trailer of speed-1.And immediately this phrase caught my attention - "What do you do?.... What do you do?".
When things go horribly wrong,when you seem to have no control over the events that are shaping up, What do you do?... What do you do?".


"Nothing splendid has ever been achieved except by those who dared believe that something inside them was superior to circumstance. "
Bruce Barton


Saturday, July 28, 2007

Spinner's End



Its for the first time after re-reading the book for the second time that i feel fit to write this one last post about the man that was Severus Snape.Many a people have asked me , how does it feel like to be right , to know that you were guessing at the truth for the past two years , without any clue , to them i say , i have moved on. I have left the fantasy world of harry potter . I started reading the book from 2001 , long before most of my friends had even heard of it , i started with the 3rd one.
And ever since that , there had been a growing fondness for the one mysterious potions master, who was evil and good , misunderstood and predictable at the same time and yet trusted by the one person that mattered. Someone who was trusted by one and only one person and detested by all.
The enigmatic Alan rickman personified severus snape to its fullness.

This is all i will ever write about the enigmatic Severus Snape.

Tuesday, March 27, 2007

Severus Snape Vindicated


codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,40,0"
width="500" height="193"
id="Countdown Snape">






Sunday, March 18, 2007

Eight most Essential FireFox Extensions

  • BugMeNotBypass compulsory web registration with www.bugmenot.com

This is a very useful extension to have when encountered with login pages that are scattered all over the www. If u doesn’t want to end up receiving countless number of registration and confirmation seeking emails just for a download or for a precious piece of information you seek, BugMeNot is for you. When installed it appears in the right click menu and when encountered with a login form it checks with a user generated database and most of the time comes up with a valid login id.You can submit your login details to BugMeNot too to grow and increase its usability.

Sites I found that are supported by bugmenot include some very famous ones like cooltoad and obscure ones like digitalantic , xpressurself.

  • Del.icio.uskeep , share and discover all your favourite things

A social book marking site that’s very much useful while searching for those obscure but useful sites that Google doesn’t come up with or the ones it filters out. Users can submit their own bookmarks to share and can access their bookmarks from anywhere through the internet.

  • FlashblockReplaces flash objects with a button you can click to view them

For those who browse the internet with volume based plans, Flashblock allows you to block those flashy ads that eat up MBs .A play icon notifies the presence of flash content and clicking over it allows the user to play it.

  • Google Toolbar FireFox-take the power of Google with you anywhere on the web!

Search using Google without ever having to go to google.com. Although most present day browsers provide integrated search engines (IE7,Firefox2,Opera), the Google toolbar comes with an array of useful and handy easy to locate gadgets like autofill- fills registration details in a jiffy, search Google images, news,…, the latest version has Google suggest integrated in it. Comes with a spellcheck feature and an atom feed subscriber.

  • IE tab
Did you know that the web looks different to different people depending on the medium through which they are looking?, in this case different browsers give different views for the same website. Handy firefox extension that brings the internet explorer inside it.
  • ScrapbookHelps you to save web pages and organize the collection

A magnificent extension that is so cool that it has been referred in the ‘the Hindu’ netspeak. Scrapbook allows users to capture the current page they are viewing, including images, the pages itself are editable, so it’s not a mere screenshot. Using scrapbook one can capture a whole website locally by pursuing the links present.

  • WebdeveloperAdds a menu and a Toolbar with various webdeveloper tools

Handy for web developers with a fantastic collection of validators and tools. You would amaze at the number of tools in a single extension, that too every bit of it useful.

  • Febe - Firefox Extensions Backup Extension

And finally to top it all, the extension that allows you to save and backup all these fantastic addons.Firefox Extensions Backup Extension! , saves all extensions as installable .xpi files.

Convert your Windows XP to Windows Vista

picture courtesy :R.Srijith


VISTAMIZE YOUR XP




picture courtesy:R.Srijith

Now that the windows vista has been launched finally and is being seen more and more in the computer peripherals around you, what should the envious ones whose systems are still in the archive era of 256 MB RAM with no graphics card on board do?

Of course make their XP at least look like VISTA, and here is a reliable way on how to go about it.

The vista transformation pack 6 is a highly reliable conversion tool that makes your XP into something like VISTA and yes it converts your xp to something that’s not VISTA nor XP. You’ll be left somewhere in the middle, with a cool new look and cool gadgets like a sidebar that offers a wonderful collection of utilities. To top it up, install the TOPDESK utility and the transformation is complete. The TOPDESK gives the aero effect, the much proclaimed ALT+TAB effect, again the xp way. Don’t expect the perfection of the real thing, but this as close as you can get.

So why should you be weary?

The creators say it does not contain any spyware or an adware, but they do say that they will not be taking any responsibility for anything gone wrong whatsoever. You must be aware that the utility enhances looks by drawing on the system resources and tweaks your system files to a level that can create system instability. It could crash, so backup your precious data on your system drive.AND there’s no uninstall. If the system crashes you grotto reinstall. You forgot to back data? Try using a Linux live cd and move as much as possible to other drives from your system drive.

We tested the transformation pack on 3 systems and none have crashed and all have worked flawlessly until now, on a dual core 2 GB RAM laptop, on a 512 MB RAM desktop and on a 256 MB RAM desktop with shared video memory.

So if your system comes in this category, then go ahead get that new looks and hey it doesn’t cost you anything ,except may be some unused computing power , its free and open and they do provide full and free updates.

P.S :TOPDESK is not a free utility.
Download vista transformation pack 6 from here

The 15 Essential UNIX commands

The 15 Essential UNIX commands


  1. man - show manual for a command, example: ‘man ls’ hit ‘q’ to exit the man page.
  2. cd - change directory, example: cd /etc/
  3. ls - list directory, similar to dir on windows. example: ls /etc, ‘use’ ls -l /etc to see more detail
  4. cp - copy a file or directory, example: cp source dest if you want to copy a directory use the -R option for recursive: cp -R /source /dest
  5. mv - move a file, example: mv source dest
  6. rm - remove a file, example: rm somefile to remove a directory you may need the -R option, you can also use the -f option which tells it not to confirm each file: rm -Rf /dir
  7. cat - concatenate, or output a file cat /var/log/messages
  8. more - outputs one page of a file and pauses. example: ‘more /var/log/messages’ press ‘q ‘to exit before getting to the bottom. You can also pipe to more | more from other commands, for example ‘ls -l /etc | more
  9. scp - secure copy, copies a file over SSH to another server. example: ‘scp /local/file user@host.com:/path/to/save/file’
  10. tar - tape archiver, tar takes a bunch of files, and munges them into one .tar file, the files are often compressed with the gzip algorithm, and use the .tar.gz extension. to create a tar tar -cf archive.tar /directory, then to extract the archive to the current directory run tar -xf archive.tar to use gzip, just add a z to the options, to create a tar.gz: tar -czf archive.tar.gz /dir to extract it tar -xzf archive.tar.gz
  11. grep - pattern matcher, grep takes a regular expression, or to match a simple string you can use fast grep, fgrep failure /var/log/messages, I'm usually just looking for a simple pattern so I tend to use fgrep more than regular grep.
  12. find - lists files and directories recursively on a single line, I usually pipe grep into the mix when I use find, eg: find / | fgrep log
  13. tail - prints the last few lines of a file, this is handy for checking log files tail /var/log/messages if you need see more lines, use the -n option, tail -n 50 /var/log/messages you can also use the -f option, which will continuously show you the end of the file as things are added to it (very handy for watching logs) tail -f /var/log/messages
  14. head - same as tail, but shows the first few lines the file
  15. vi - text editor, there are several text editors such as emacs, and nano, but vi is usually installed on any server so its a good one to learn. To edit a file type vi file to edit a line press Esc i then to save changes and exit use Esc wq, or to quit without saving use Esc q!. There are a million other commands, but that will enable you to edit files at a basic level.

Friday, February 16, 2007

Is it possible?

  • i need to create an online bingo, to be played between two computers connected through lan

Monday, February 12, 2007

New Linux Kernel Will Increase Intellectual Superiority

By Brian Briggs



Santa Clara, CA - A recent survey of Linux users found that the two main factors in their migration to Linux was its stability and that it made them feel intellectually superior. Developers promise that along with USB support there will be increased intellectual superiority in the upcoming 2.4 kernel release AKA the "Hubris" kernels.

"Many users complained that in our previous release that we sacrificed some intellectual superiority in the name of 'ease of use'. We aren't going to make that mistake in this release," said kernel programmer Johan Klens.

IQ Chart"Programmers have worked very hard in the latest kernel release trying to make even simple tasks more difficult," continued Mr. Klens, "This release is going to include the "ocsh" - the obfuscated C shell, sure to be a favorite of intellectual superiors. In addition to inputting commands as obfuscated C code, users can also input commands in binary directly to the registers. It took me 10 minutes to code the directions to 'cat' using ocsh, but it was worth it!"

"I was impressed by the stability of Linux," said Thomas Azizi "and since I'm a loser in pretty much every other facet of my life, gloating about my OS choice makes me feel great."

"Let's face it. Linux isn't for dummies," said Linux advocate Dieter Braun, "There may have been a Linux for Dummies book, but I doubt it sold a single copy. I'm sure Windows for Dummies was a best seller."

Tuesday, February 6, 2007

Tryst with ubuntu 6.06

To the point :
the cd has some problem with it , its getting stuck . Work around - partition using the applicaion in the live cd called 'gpart'.

installed the system after a week long exercise.

There's nothing inside ,No music players ... not even a 'gcc'. everything must be downloaded.

Need to install java - how?
Applications->system->synaptic manager.

Sorry nothing there remotely connected to java. I downloaded and installed everything that began with java... , no use . (i was looking for javac - java compiler).
Wasted some 30 Mbs.


Began searching for "ubuntu 6.06 - install java" most of them were .deb files. absolutely no use ,full kachara , kept on searching - found this out but it cost me a 100Mbs worth download but voila java is home.

install java my way --->

On Debian/Ubuntu Linux for example all you need to do is make sure that your apt-get is pointed at the right place. In your /etc/apt/sources.list add in the following (and make sure you are okay with adding in stuff that is not in the default environment).

( you need to login as root for editing this file since otherwise its read only , and no the 'su' aint working ,so dont bother with that.How do you login as root? I HAVE NO IDEA. but booting in ubuntu recovery mode logs you in as root. But is that acceptable? and what about security? )

deb http://us.archive.ubuntu.com/ubuntu dapper main restricted
deb http://us.archive.ubuntu.com/ubuntu dapper universe multiverse

After this have apt updates its repository

sudo apt-get update (sudo is working fine though)

And finally, just tell it to install java :)

sudo apt-get install sun-java5-jdk


After this the rest of the process will display a dialog that will require you to accept the license agreement. When you do, the rest of the setup will happen on its own.

When you're on the command prompt type

javac -version

or

java -version


You should be good to go! Finally we have an easy way to install Java on the various Linux variants without having to fight with fakeroot and the other foolishness. Took Sun a criminally long time to do this, but I (not me - i have reasons to think otherwise) certainly thank them for it.

About Me

i am sarath a.This blog enlists motivational or inspirational works. GO For Maximum mischief.