Here are a few basic ideas that might help anyone having trouble with CPU or motherboard driver problems.
First download the latest chip drivers for the motherboard and install them. (Flash the motherboard BIOS). You can get these from the motherboard web site. They are not OS specific although you may need to run Windows to install them. Hopefully they can be installed from a boot floppy or something similar. If not then just shove a Windows disk into this computer long enough to flash the motherboard BIOS, then reconnect the Linux disk.
Then get into the motherboard CMOS setup and turn off APIC and ACPI. Look around in the motherboard's CMOS setup for other motherboard features that can be turned such as suspend to ram.
Make sure that the motherboard is set to use the latest version of SMP management. I don't recall off hand what that version is but the number 1.4 comes to mind.
Make sure that the motherboard manages IRQs. Some motherboards do more in this area than others. Check to ensure that the other protocols such as USB and LPT are set to use the latest version or are turned off.
Now as for Linux, if the CPUs are 64 bit then consider whether you want to use a 64 bit kernel or a 32 bit kernel. If you have a choice you may want to select the one that you are currently not using.
Make sure that the version of CentOS/Linux has all of the latest driver patches available for that kernel version.
See if you are running special function software such as athcool. Turn it off.
Hopefully you can see the method that I've got in mind. Make sure that the motherboard drivers/BIOS are up to date, then make sure that the motherboard settings aren't getting in the way, then make sure that the Linux drivers are up to date. Simplify your software environment until the problem goes away, then add back only what you need.
Or change Linux distributions.