A common cause of slow performance in todays PC's is a lack of available RAM but with the lower cost of RAM today, this doesn't not need to be an issue for most users.  The price of RAM has fallen dramatically over the years and, assuming your PC is not too old, this can be a very cheap upgrade that makes some very big differences to your PC performance.

If you are looking to upgrade the RAM on your PC, first of all you need to identify what type of RAM chips are currently installed on your system. Here we are going to discuss about main type of RAMs which are being used now-a-days.

EDO RAM – Extended Data Out or EDO RAM was introduced in 1995 as a modified version of FPM RAM. EDO RAM is almost abolished and it was used on early version of Pentium based systems. It looks as follows and the width is around 108mm and comes with a single notch.

SDRAM – Synchronous Dynamic RAM or SDRAM operates by synchronization with memory buses. SDRAM was introduced in early 1996 and was quite popular around 2001 mostly with Pentium and Celeron systems. SDRAM is around 133.8mm wide and comes with 2 notches. The basic shape of SDRAM is as follows.

DDR RAM – After the SDRAM, Double Data Rate or DDR RAM was introduced with double clock rate and better data transfer ability. It is widely used with Pentium and AMD based system as a standard memory module. The width of DDR RAM is almost same as SDRAM but little thicker and comes with a single notch as follows.

DDR2 RAM – It’s the next upgraded version of DDR RAM and a standard for multi-core CPUs. It’s now available in more than 800Mhz speed and up to 4GB capacity in a single RAM stick. Size is near as DDR RAM and comes with single notch.

Extract and pics from MWolk