BIOS settings vsw CPU performance!?

I’m running a FIC DS-11 board w/ a 900MHZ T-bird pkg’d as Slot A. The only way I can get the CPU to perform at normal performance is to set the BIOS to default. If I change ANYTHING, CPU performance drops to 10-15% of expected, making the system essentially unuseable. I’ve tried 3 T-bird & 2 “classic” Athlons, changed board for an MSI K7 Pro, completely reinstalled Win Me & all components. What’s wrong???

Ralph Mason