well it is hard to say what is better, it depends what you want to spend. I use RDRam and I really like it. It is very fast and I only have 128mb but I have never run out and the 128 has suited me fine. The only probably is that it is expensive (but less and less everyday). Quite some time ago when Rambus came out with RDRam meny people were unhappy that it required a second mortgage to stock your system with an adequate supply (at least $125 or so for 128mb)... but times have changed. The prices have come down significantly, but they are still more expensive than SDRam... although the last I saw was that you can get some 128mb non-ECC for about $30 or so. Fortunately now intel makes a mobo that will take the P4 and SDRam, so you have a choice between the two, so it depends if you want to spend the extra $$ for the RDRam. RDRam is I think 10x faster, so with prices the way they are now it may be worth it. I would suggest the RDRam, but that is just me.