I have been wrestling with this problem for 3 days and I still am not sure why this is going on. I installed an AMD XP 2600+ Throughbred-B 256L2 in my computer about 10 day ago to replace my xp1800 and my MB reconized it and set up at 12.5X166 (2.083 ghz) like it should be. A few days ago I put a different cpu cooler on it and when I restarted it it changed to 11.5X166 (1.917). Its is now locked at 11.5X and will not show a change unless I overclock or underclock. The cpu is identified as an Xp1800 @ what ever speed I happen to be running at the time in Sandra and Win ME. I think this is a bios problem But I have not reflashed it inseveral months. The chips Id is AXDA2600KV3D. Any ideas how to remedy this?:frown: