Do I have a bad motherboard or a bad CPU? (STOP 0x00000101 and 0x00000124)

I just built a new system and I'm getting very frequent STOP errors. The STOP errors I've hard are 0x00000101 and 0x00000124, which are both Machine Check Exceptions.

I know that I have a hardware error, but I'm not sure if it's the CPU or the motherboard that's the problem. I don't have another CPU of the same socket handy to swap and test.

The reason I suspect the CPU is because in the event log I see a log of these:

A corrected hardware error has occurred.

Reported by component: Processor Core
Error Source: Corrected Machine Check
Error Type: Cache Hierarchy Error
Processor ID: 1

The details view of this entry contains further information.

From what I've read, that could be a BIOS issue, but it certainly sounds like a CPU issue.

The motherboard is a GIGABYTE with AMD SB700 southbridge. The CPU is an Athlon X2 7750.

My understanding is that the CPU is a re-branded X4 with two cores disabled, probably because they are faultly.

I want to RMA the faulty part, but I'm not sure which it is. Anyone care to guess?

UPDATE: RESOLVED - After replacing the motherboard, the problem turns out to be "Cool 'n Quiet". Disabling "Cool 'n Quiet" in the BIOS suddenly resolved the issue. No more BSODs.

Two ways to look at it:

1) The CPU almost never goes bad. We've replaced 36 desktop motherboards this year. We've only replaced 1 bad CPU. The CPU failing is very, very rare.

2) In my career/experience, I have never had a bad CPU that allowed the computer to get as far as a blue screen. When bad CPU's happen, the machine does not boot.

I can't site anything specific on those two pieces of advice beyond general experience, as I have not seen that specific error message before, but my career says bad motherboard.