What about newer types of RAM?
Today's computers have such fast processors that new types of memory are being developed just to keep up with them. RDRAM (or Rambus, for short), a higher access speed memory originally designed for graphics applications, has now found its way into some cutting-edge (1GHz and above) systems.
However, if you decide to go with RDRAM, you won't be able to swap out your SDRAM DIMMs and plug Rambus memory in their place. To take advantage of the RDRAM, your computer's motherboard must have a chipset that can support it, as well as the proper Rambus controller circuitry.
RDRAM is packaged in RIMMs (Rambus Inline Memory Module), which are roughly the same size and shape as DIMMs. A few dozen manufacturers--including Hitachi, IBM Kingston, Micron, NEC, Samsung, Toshiba, and Viking--are already in the RIMM business. One feature that's particular to RIMMs is a heat sink.
Since individual chips are mounted more closely together on RIMMs than on DIMMs or SIMMs, manufacturers had to come up with a way to direct heat away from them. That's where the sink comes in.
Another newcomer to the RAM game is DDR SDRAM (Double Data Rate SDRAM). DDR SDRAM is roughly twice as fast as standard SDRAM, and like RDRAM, it is not compatible with older systems. If you want to upgrade your RAM to DDR SDRAM, your PC's motherboard needs to support 184-pin DIMM slots, and your processor must be one of the newer ones designed to handle the extra bandwidth (such as the 1GHz and faster AMD Athlon chips) or all that speed just goes to waste. PC1600 DDR SDRAM is made for motherboards and processors with a 200MHz (100 MHz doubled) bus, and PC2100 DDR SDRAM is designed for motherboards and processors with a 266MHz (133MHz doubled) bus.
PC2100 RAM will work on motherboards with a 100MHz bus, but you won't see any dramatic boosts in performance.
