Explain DDR2 Speed

[Xan]

I am quite familiar with the speed of SDRAM and DDR, but not DDR2. I'm in the market for a new AMD AM2 setup and I am not sure which RAM speed I need to purchase for best performance. I will NOT be overclocking - just factory default speeds.

I will of course be buying Corsair RAM. Great quality RAM.

I have seen Corsair XMS2 listed speeds:
8500, 8000, 6400, 5400, and 4300.

also some of these have "EPP - Enhanced Performance Profiles"

I'm looking at getting the ASUS M2N32-SLI Deluxe.

 

[(cf)Eclipse]

maximum stock speed for am2 is ddr2-800, pc6400.. if you're not overclocking, i think i'd go for one of those with 4-4-4 timings?
http://www.newegg.com/Product/Product.asp?Item=N82E16820231073