I have an 8IHXP, PC800 RDRAM, and a B0 2.53. The highest I can get stable is 145 FSB for 2.75Ghz. Any higher and my RAM starts to crap out, since it doesn't seem to like anything higher than PC870. I'm using two sticks of Samsung PC800 40ns. However, I am not overvolting the ram, and I am using stock cooling. Hope that helps you decide, but as always, YMMV.