ive got some el cheapo stuff i pulled out of a gateway system, 2*256 pc2700, it is stock 166 and ive pushed it all the way to 220 completely stable on memtest for 4 hours(im too impatient to test for days ), this RAM is godly i didnt even change the timings from stock to get to 220, and it runs fully stable... so i guess its all luck of the draw, this stuff coulda crapped out at 196 but it keeps trucking along...