To make your Processor and computer work, memory is crucial. It determines what programs your computer can run and how fast it can run them. Memory holds both the data that needs to be processed, as well as the data that has already been processed. In your PC there are various types of memory each taking a different form and function. The memory that concerns us is the type that you must purchase separately. In its current incarnation the most popular memory used today are know as DIMMS. (There are also the Rambus memory modules that Intel has been trying to push, but they are pretty expensive and Intel seems to be backing away from them as they have not really caught on.)

As Computer processors have grown faster so has the need for faster memory. (Hence the terribly overpriced Intel Rambus system.) The following will describe the various types of memory currently being used to fill that need

The current standard for Computer Memory use is known as SDRAM (Synchronized Dynamic Ram). These are normally arranged into modules known as DIMMS. The standard speed is currently 100MHz known as PC100. There are also PC133 modules (running at 133MHz) being sold today for a slight premium, the PC133 is worth buying if you are building a new computer but the performance margin is negligible enough that you shouldn't go out and buy some to replace your current PC100 Modules. The future of SDRAM remains to be seen as the push towards greater memory speed requirements might render the whole SDRAM interface obsolete (though not in the next two years at least).

DDR (Double Data Rate) SDRAM represents a somewhat radical redesign of memory, to address not the need for "MORE" memory capacity but "FASTER" memory capacity. In other words, there had to be a way to get more of the stuff stored inside the memory chip out. DDR SDRAM was designed to take advantage of a new Motherboard design allowing information to be transmitted up to twice as fast. This redesign can make a computer about fifteen percent faster than one using standard PC133 SDRAM. DDR SDRAM is still quite expensive and is used on mainly high end machines.

Developed by Rambus and pushed by Intel, this is perhaps the most maligned technology product in recent years. It sets out to do what DDR SDRAM is trying to do, namely increase memory bandwidth to speed things up. The problem with RDRAM is that it takes awhile to get things going. Namely it suffers from Latency. That it since the memory has to pass through various buffers, each of which has to do its own processing, even though more memory is traveling they are traveling more slowly. Because of this Latency issue, not only is DDR SDRAM currently about forty percent cheaper than RDRAM, it is also about five to ten percent FASTER!. Intel is pushing this format however, and its current Motherboards only work off this technology. Things are looking up though, as prices for RDRAM are expected to drop as more become available, and the Latency kinks are reportedly being worked out. RDRAM has more potential then DDR SDRAM and while it is not an extremely attractive option today, it is currently the only format projected to be able to meet the needs of future computer generations.