RDRAM (a.k.a. rambus) can be confusing but is basically simple once you know the simple basics. Let me try to help you understand this unique memory that is making a strong comeback.

This memory comes in these speeds. 600, 700, 800. These are better known as PC600, PC700 (PC711), PC800. PC800 being the fastest and most sought after. The sizes they are available in are 64MB, 128MB, 256MB, 512MB. They have 184 pins.

Motherboards that use RDRAM have 4 memory slots. All 4 slots must be filled or the computer will not run. All 4 slots can be filled with memory or 2 can be filled with memory and 2 can be filled with CRIMMS. Crimms are blanks that have no memory incorporated within them. They basically complete the circuit on the motherboard and must be used. But most importantly, RDRAM must be installed in 'like' pairs. For example, you must use 2 x 128’s or 2 x 512’s etc, in the first 2 slots. You can not use 1 x 128 and 1 x 512 in the first 2 slots nor can you use a PC600 and a PC800 together in the first 2 or last 2 slots.

RDRAM also comes in 1066 but it is not as commonly used.

RDRAM also comes in ecc and non-ecc. ECC is an error correction control built in to the memory module but can create more problems them you bargained for. Motherboard manufacturers recommend larger memory modules (256MB and up) to be ECC. I personally do not agree. I use all non-ecc. Also, if you install an ECC module with a non-ecc all that will happen is your motherboard will shut off the ECC function. ECC memory may also cause your computer to run slower.