Sorruy, I thought I mentioned. It is a K7S5A so it supports both types. The reason I said PC2700 over PC2100 is that even though I have a K7S5A I still want to overclock. Buying the RAM would be a stepping stone to getting a new mobo, as it isn't worth buying a SDR motherboard with overclocking features as they aren't as good as the DDR ones. and I would be ditching myself with crap goods. I was hoping to get a NF2 mobo once I raise the cash after this and then let rip with this CPU (XP1700+ unlocked DUT3C) which should be good for about 1.8/1.9 with the cooling I have on it.