Whether it's advertised as PC3000 or PC3700, if it uses Winbond BH-5 chips, it doesn't matter. Winbond BH-5 chips are 5ns chips, they take 5ns to complete one clock cycle. They are rated at 200MHz (1000/5) and thus will do DDR400. Anything higher then this is an overclock, and anything lower is an underclock. Mushkin Black Level 2 is the only memory promising Winbond BH-5 chips. With Buffalo PC3700 and Kingston HyperX 3000 said to possible have the chips as well. Anything else no longer assembles modules using these chips (Corsair uses Winbond CH-5 chips). Mushkin is also beginning to run low, which is why they did not use Winbond BH-5 chips with their high-performance registered PC3200. But all black level 2 Mushkin memory (of PC3200 and PC3500 given speeds) use Winbond BH-5 chips.