I'm running Corsair PC2700C2 at DDR387. I was running DDR400, but my DF (distributed folding) client kept crashing, so I had to back off my CPU from 150MHz FSB/2.7GHz to 145MHz/2.61GHz. At 2.7GHz it was totally stable for Windows apps (passed Prime95 for over 12 hours) but not stable enough to run a DC client that kept the CPU at 100% 24/7. I could have upped my vcore a bit (running it at 1.62v actual) and kept the 2.7Ghz but I need this thing to last a few years.