Computer Memory Guide

Computer memory can be a little confusing. Here is a list of all the different memory chips you can buy these days. As you can see there are a few different types.


The best place I've found to get computer memory online is TigerDirect. All the different types can be bought at some of the best prices on the internet.

You must get the right type for your motherboard. There are also different prices and performances for each type so read on to get the full story.

SD Computer Memory:

This is the oldest, slowest and most common memory type. If you have a Pentium III then you will use this type. PC100 is old and only for Pentium IIs do not buy this memory for a newer computer such as a pentium III or 4.

PC133 is the newer and slightly faster type get this memory for your Pentium III or Celeron. CAS2 or CAS3 spec refers to the memory latency. CAS2 is a bit faster so get this for better performance. The third spec is the amount in megabytes per stick/chip.

A new computer should not have less than 128mb of total memory. You can get ECC versions of this memory that check for errors. This adds to the cost, is more reliable but is only used for servers.

Rambus Memory (RD RAM):

This is a special type of memory that is only used by Pentium 4 computers. You must install two chips at once. This is becoming quite a rare memory type so only buy some of this if you're sure you have a Rambus compatible motherboard.

Rambus memory is very fast and is some of the fastest memory you can get for the Pentium 4. There is ECC Rambus as well if you want to build a reliable server.

DDR Memory:

DDR memory is the most common form used with AMD Athlon processors. The new Canterwood and Springdale motherboards also support dual channel DDR 400/PC 4200 DDR ram.

DDR memory is quite a bit faster than SD memory so I recommend you get this type with your new Athlon or Duron computer. DDR memory is also a much better choice than SD Ram with a Pentium 4 system as well. Don't worry almost all new computers come with some variety of DDR Ram.

What can be confusing is that there are different speeds of DDR Ram. Just like CPUs. Current motherboards are now accepting the latest speeds of dual-channel DDR2 667 memory. If you put this on an older computer; the RAM will run at slower speeds for older computers, so don't buy more speed than your computer can support..

If you're just going to upgrade your computer it is unlikely you will need DDR 667. Just save yourself some cash and buy DDR 400.

This wraps up my computer memory guide. Once you have some memory, from TigerDirect of course, you can read my computer memory install guide here.



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