• An example of a 184-pin DIMM chip with memory blocks on both sides.ram 2 image by PeteG from Fotolia.com
  
  For a computer to be able to carry out the instructions it receives, it needs to have enough "hands" to be able to do the job. RAM, or random-access memory, can carry out and hold information until the computer is ready to use it. The more "hands" the computer has, the more it can do--for example, running multiple programs simultaneously--and the faster it can do it. RAM's efficiency is a result of the specific type being used; each has a different architecture and speed.
  
  

SIMM Chip

• SIMM stands for Single Inline Memory Module. Older computers use SIMM chips almost exclusively. SIMM chips are 32 bits wide, versus the typical 64-bit bus of the DIMM chip. A bus is a data lane that connects two pieces of hardware within a computer. The bigger the bus, the more information that can be passed through and the faster it operates. To power a more modern Pentium microprocessor, two SIMM chips would be required to be the equivalent of one DIMM chip.
  
  

DIMM Chip

• DIMM stands for Dual Inline Memory Module. Because DIMM chips have a 64-bit path, they are better suited for Pentium processors. DIMM chips were designed to replace the need for two SIMM chips to satisfy a 64-bit bus. DIMM chips have separate electrical contacts, as opposed to SIMM chips that have redundant electrical contacts. DIMM chips are better suited for modern computers than SIMM chips because of their efficiency.
  
  

SDRAM Chip

• SDRAM stands for Synchronous Dynamic Random Access Memory. SDRAM supports a higher bus speed, so it has become the RAM of choice for many newer computers. SDRAM is designed to read and write more efficiently than the other forms of RAM because of the way it is tied to the system clock. SDRAM runs in synchronization with the system clock, allowing it to process information much faster.
  
  

RDRAM

• RDRAM (the R meaning Rambus, also known as RIMM and developed by the company of the same name) is a specialty memory that is only available in selected applications and only with motherboards that have the proper chip set. This makes implementing RDRAM more expensive since those boards tend to be on the pricey side. They have 184-pin and 232 pin architecture and is faster than SDRAM, which gives it a slight edge for applications such as gaming, audio, and video production.
  
  

XDR2 DRAM

• XDR2 is for high performance machines, able to reach over 500 gigabytes of bandwidth and data rates from 6.4 to 12.8 Gbps (gigabits per second). Power efficient, it's able to perform at 30 percent lower power than the highest GDDR memory.