AMD New Processors

Almost stealthy, AMD has launched four new processors. See them below.

Processor	Model	Internal Clock	L2 Cache	L3 Cache	Price
Phenom X4	9750B	2.4 GHz	512 KB per core	2 MB	US$ 250
Phenom X3	8759B	2.4 GHz	512 KB per core	2 MB	US$ 200
Athlon X2	5600B	2.9 GHz	512 KB per core	-	US$ 125
Athlon X2	4850B	2.5 GHz	512 KB per core	-	US$ 100

see more in http://www.amd.com/us-en/

Compare DDR2 and DDR3

Compare DDR2 and DDR3

Considering the ever growing need of speed and efficiency, understanding Double-Data-Rate (DDR) memory is important to system developers.

Characteristics
DDR memory's primary advantage is the ability to fetch data on both the rising and falling-edge of a clock cycle. DDR1, DDR2, DDR3 memories are powered up with 2.5, 1.8 and 1.5V supply voltage respectively. Temporization is another characteristic of of DDR memories, memory temporization is given in a series of numbers, such as 2-3-2-6-T1, 3-4-4-8 or 2-2-2-5 (CL-tRCD-tRP-tRAS-CMD) for DDR1. These numbers indicate the number of clock pulses that it takes to perform a certain operation- smaller the number faster the memory.
CL - Column Address Strobe, tRCD - Row Access Strobe to CAS delay

Type of DDR Memories

DDR1 with a maximum rated clock of 400MHz and a 64bit(8 bytes) data bus ( Now it is obsolete) .
DDR2 with a maximum rated clock of 800Mhz and a 64bit(8 bytes) data bus. DDR2 memory is physically incompatible ith previous generation of DDR memories.
DDR3 starts where DDR2 left off(800 MHz) and bring the speed up to 1.6 GHz. The 1.5V DDR3 voltage also save power( it will work in 1.36v also)

DDR2 Vs DDR3

DDR2 memories include 400Mhz, 533Mhz, 667Mhz and 800MHz versions, while DDR3 includes 800MHz, 1066Mhz, 1333MHz, and 1666Mhz versions.

Besides the enhanced bandwidth, DDR3 also uses less power than DDR2 by operating on 1.5V(16.3% reduction)

A newly introduced automatic calibration feature for the output data buffer enhances the ability to control the system timing during variations in voltage and temparature.

DDR3 devices introduce an interrupt reset for system flexibility.

Difference in the CL ( Column Address Strobe)

The controller in DDR2 memories works by preloading 4 data bits from the storage are(prefetch) while DD# works by loading 8 bits in advance.

For more details read ECN August 2008, Understanding RAM timings (article) www.hardwaresecrets.com/article/26/1 and powerelectronics.com/mag/power_ddr_memories_require/

Installing PHP5 and Apache on Ubuntu

Installing PHP5 and Apache on Ubuntu

If you are doing any kind of PHP development, you'll almost always be using Apache along with it. Here's the way to get PHP up and running on your Ubuntu box.

From a command shell, you will run the following commands:

sudo apt-get install apache2

sudo apt-get install php5

sudo apt-get install libapache2-mod-php5

sudo /etc/init.d/apache2 restart

Your web files will now be found in /var/www/

Installing Tomcat 6 on Ubuntu

Installing Tomcat 6 on Ubuntu

If you are running Ubuntu and want to use the Tomcat servlet runner, Some times the apt will not work correctly. You can try the following method it will work.

Before you installing Tomcat you must install Java. I would assume if you are trying to install Tomcat you've already installed java, otherwise install Java as per my previous posting. If you aren't sure about your Java installation, you can check with the dpkg command like so:

dpkg --get-selections | grep sun-java

This will give you this output if you already installed java:

sun-java6-bin install
sun-java6-jdk install
sun-java6-jre install



Installation

Now we'll download and extract Tomcat from the apache site.

wget http://apache.hoxt.com/tomcat/tomcat-6/v6.0.18/bin/apache-tomcat-6.0.18.tar.gz

tar xvzf apache-tomcat-6.0.18.tar.gz

The best thing to do is move the tomcat folder to a permanent location. I chose /usr/local/tomcat, but you could move it somewhere else if you wanted to.

sudo mv apache-tomcat-6.0.18 /usr/local/tomcat

Tomcat requires setting the JAVA_HOME variable. The best way to do this is to set it in your .bashrc file. You could also edit your startup.sh file if you so chose.

The better method is editing your .bashrc file and adding the bolded line there. You'll have to logout of the shell for the change to take effect.

vi ~/.bashrc

Add the following line:

export JAVA_HOME=/usr/lib/jvm/java-6-sun

At this point you can start tomcat by just executing the startup.sh script in the tomcat/bin folder.

Install rpm files in linux ubuntu hardy

Install rpm files in linux ubuntu hardy

open a terminal windows

sudo apt-get install alien

Use the following command to install your rpm file

sudo alien -i name_of_rpm_file.rpm

You can also convert rpm file to deb file
sudo alien -k name_of_rpm_file.rpm

for install deb file use
sudo dpkg -i name_of_created_deb_file.deb






proc filesystem tutorial Part-2

$ ls -l /proc will give a listing of files inside /proc

A brief walkthrough of the most important files

• cmdline - The command line issued when starting the kernel.

• cpuinfo - Information about the Central Processing Unit.

• dma - Contains information about all DMA channels available, and which driver is using it.

• filesystems - Contains short information about every single filesystem that the kernel supports.

• interrupts - Gives you a brief listing of all IRQ channels, how many interrupts they have seen and what driver is actually using it.

• iomem - A brief file containing all IO memory mappings used by different drivers.

• ioports - Contains a brief listing of all IO ports used by different drivers.

• kcore - Contains a complete memory dump. Do not cat or anything like that, you may freeze your system. Mainly used to debug the system.

• kmsg - Contains messages sent by kernel, is not and should not be readable by users since it may contain vital information. Main usage is to debug the system.

• ksyms - This contains the kernel symbol table, which is mainly used to debug the kernel.

• loadavg - Gives the load average of the system during the last 1, 5 and 15 minutes.

• meminfo - Contains information about memory usage on the system.

• modules - Contains information about all currently loaded modules in the kernel.

• mounts - Symlink to another file in the /proc filesystem which contains information about all mounted filesystems.

• partitions - Contains information about all partitions found on all drives in the system.

• pci - Gives tons of hardware information about all PCI devices on the system.

• swaps - Contains information about all swap partitions mounted.

• uptime - Gives you the uptime of the computer since it was last rebooted in seconds.

• version - Gives the exact version string of the kernel currently running, including build date and gcc versions etcetera.

And here is a list of the main directories and what you can expect to find in there:

• bus - Contains information about all the buses, hardware-wise, such as USB, PCI and ISA buses.

• ide - Contains information about all of the IDE buses on systems that has IDE buses.

• net - Some basic information and statistics about the different network systems compiled into the system.

• scsi - This directory contains information about SCSI buses on SCSI systems.

• sys - Contains lots of variables that may be changed, including the /proc/sys/net/ipv4 which will be deeply discussed in this document.

As you can see, there is literally hundreds of files in the /proc filesystem that may be read and checked for information, and we haven't looked at half of them here.

linux proc filesystem tutorial Part-1

A brief /proc walkthrough

The /proc filesystem contains a few basic directories and entries

$ ls -l /proc

First of all, the filesystem contains a large set of numbered directories that come and go. These numbered directories contains information about all of the currently active processes on the machine. When a new process is started, a new directory is created in the /proc filesystem for it, and a lot of data is created within it. eg: commandline with which the program was started with, a link to the "current working directory", environment variables, where the executable is located, and so on.

Most of the information in the files are readable , except a few of them. However, a few of them you should not touch, such as the kcore file. The kcore file contains debugging information regarding the kernel, and if you try to 'cat' it, your system may very well hang up and die. If you try to copy it to a real file on the harddrive, you will very soon have filled up your whole partition, and so on. What all of this tells you is to be very careful. Mostly, none of the variables or entries in the /proc filesystem is not dangerous to watch, but a few of them are.

A brief walkthrough of the most important files in part - 2 wait......

More gnome and apt easter Eggs in ubuntu

Another for apt

sudo apt-get moo will give output like

(__)

(oo)

/------\/

/ | ||

* /\---/\

~~ ~~

...."Have you mooed today?"...

One more
type and press enter the following in a terminal one by one

aptitude help

aptitude moo
aptitude -v moo
aptitude -vv moo
aptitude -vvv moo
aptitude -vvvv moo
aptitude -vvvvv moo
aptitude -vvvvvv moo

Virtualization made easy with ubuntu hardy

Virtualbox is a powerful virtualization tool in ubuntu hardy

Repository settings are same as my previous post (Java Installation)

sudu apt-get install virtualbox-ose virtualbox-ose-modules

After the installation is finished you’ll need to do just one of the following.

• Add yourself to the vboxdrv group (sudo usermod -G vboxusers -a username), and then re-login.
• change permissions on the vboxdrv device (sudo chmod 666 /dev/vboxdrv)

(if any failure try this commands before installing
1. sudo apt-get install build-essential linux-headers-`uname -r`
2.wget http://www.virtualbox.org/download/1.5.6/virtualbox_1.5.6-28266_Ubuntu_hardy_i386.deb
3.sudo dpkg -i virtualbox_1.5.6-28266_Ubuntu_hardy_i386.deb
4. sudo adduser $USER vboxusers)

It is worked in my core2 duo e8200 machine with 2GB RAM and INTEL G33 Motherboard
Linux kernel version 2.6.24-16

Its Great I have created virtual machine with 512 MB RAM and 8 GB hard disk , tested with my Ubuntu hardy live CD , it worked and with out any configuration I have connected to internet and browsed, and also tested open office very fast and no complications.



INSTALL SUN JAVA IN UBUNTU LINUX

INSTALLATION OF SUN JAVA 6 IN UBUNTU HARDY

Run System-->>Administration-->>Synaptic Package Manager
(if it ask for passwd enter your sudo passwod)

In Synaptic Package Manager

select Settings-->>Repositories

in ubuntu software tab select first FOUR options
(main, universe, restricted, multiverse)

select Third-party Software tab and
tick first option ( http://archive.canonical.com/ubuntu hardy partner)
and close it

Press reload button

after reloading the list
select search and type sun java
select sun-java6-bin, sun-java6-fonts, sun-java6-jdk, sun-java6-jre,
sun-java6-plugin (don't select sun-java6-doc it will make some problem)

then select apply

To work your browser plugins

Just installing new Java flavours does not change the default Java pointed to by /usr/bin/java. You must explicitly set this:

• Open a Terminal window

• Run sudo update-java-alternatives -l to see the current configuration and possibilities.

• Run sudo update-java-alternatives -s XXXX to set the XXX java version as default. For Sun Java 6 this would be sudo update-java-alternatives -s java-6-sun

• Run java -version to ensure that the correct version is being called.