So is it the same with AMD boards? In other words, if I get an AMD board with a 266MHz FSB, what speed of DDR should I get?
You'd get RAM that's rated 266MHz which would be PC2100.....more than likely you'll see it listed like PC2100(266), PC2700(333), PC3200(400), just like that. So then it basically plainly tells you what you need. In this case you need RAM that has a FSB of 266 so then you'd see PC2100(266) and boom there's your RAM. This is all for AMD as I know nothing of Intel.
Mind you when you go into your BIOS with an AMD board the FSB for the CPU will be set at 133....because 133x2 = 266 so that's how they figure out their FSB Rating for the RAM. Whatever the CPU's FSB is at, you have to multiply it by two and you'll know your RAMs FSB. Be careful though because BIOS's are different and will show different settings. I've had a BIOS where you select the RAM as 133,166 or 200 which translates into the RAM being either 266,333,or 400. The other board I had asks you for a ratio from the CPU
RAM so then you have to get the right ratio to get the right speed. If you got a 266FSB boad and CPU then your ratio would be 1:1.....I'll just stop at this point cause I don't want to confuse you. Let us know if you require more assistance.