Desktop Memory: DDR, DDR2 and now DDR3

Desktop memory: one of the essential components of a PC. DDR is defined as double data rate, and it refers to the type of memory used in most household desktop computers. There are other various types of memory such as RDRAM and XDR RAM but this article focuses on DDR and the changes it has gone through.

DDR and DDR2 are the two most commonly used types of memory. Try not to confuse GDDR (Memory sometimes advertised on graphics cards) with the similarly named desktop alternative. One such example of this is how GDDR2 does not equal DDR2. Until a couple years ago, the way you determined which kind of memory to use decided upon what type of motherboard/cpu you were using. If you were using Intel you would go with DDR2 and if you went with AMD you were stuck using DDR. (DDR is shown in the picture above)

It was not until the release of the AM2 Socket platform, when AMD finally implemented DDR2 as the new memory standard. It is now safe to buy DDR2 memory and whichever route you go, Intel or AMD, the memory will be compatible.

Differences between DDR and DDR2:

• DDR2 Data rate increased where DDR left of
• DDR400 - Fastest DDR memory
• DDR2 400-800

• Voltage has significantly decreased with DDR2
• DDR 2.5-2.8v
• DDR2 1.8v

• Prefetch size increased to 4 bits with DDR2 compared to 2 bits

For a good in depth article covering DDR vs DDR2 visit Overlocker Cafe.

DDR2 has been the standard for both Intel and AMD for a few years. As with all technology, memory is once again starting to move forward into the land of DDR3. DDR3 is raising the stakes with its even lower voltage, 1.5v; increased prefetch size to 8 bits deep and an obvious clock rate increase. DDR3 is a rare sighting due to its very expensive price tag. Thirty six DDR3 modules are currently listed on Newegg and the least expensive is 1gb value RAM priced at $150 and the price just keeps on rising from there, reaching prices close to $1000 dollars for a high performance 4gb kit. For now DDR3 is screaming enthusiast but give it a year or so and the price should be reasonable investment for consumers.