DDR1 PC3200 Crucial Ballistix, I got some on the way, BEST RAM IN THE WORLD, HAND DOWN, NO ONE CAN ARGUE THAT. BTW, Jac, nice post on RD, could not have done better myself. Can add something though. Rambus bus is circular pathway, so it never has to stop access on the RAM, however, RAMBUS RAM (RDRAM) has very high latency (40ns!!!) compared to DDR SDRAM with around 5ns or less.... So really, RD is about the same speed, and is really expensive. Also, since BUS is circular, with no stops, that means the circuit has to be completed. In otherwords, you cannot have open slots in RDRAM configurations, or else it wont work. You have to have all the same sized chips (pairs) so you could do like (2X256MB) and (2X512MB) chips together, but if you did (2X512MB) you would need chips in the other empty 2 slots. That is where the dummy chips came in, they just sat there and filled the space and completed the circuit, but had no RAM on them at all. RDRAMs next stage is codename "Yellowstone" which will run at around 2.3GHz or so, and will only have 11ns latency, making it fastest RAM in the world. However, for now, buy Crucial Ballistix, and overclock it to 250MHz (500Mhz) and it will still run at 2.5-2-2-2!!! The stuff is miracle ram, Crucial are Geniuses!