because of the way cas latency is calculated, cas 3 at 533 or 566 (can't remember) is equivalent to cas 2 at 400, ddr2 prices are dropping but i don't know how great an investment they'll be, amd will probably stay on ddr2 for at most 2 years, earlier this year intel said it would phase out ddr2 if amd skipped it and went to ddr3, ddr2 is considered to be a poor standard