System freezes with new CPU

[gamerdude1989]

hi guys

Got an old HP XW6400 Workstation that has twin xeon's..
Two Xeon 5160 Dual Cores to be exact..
That im just playing around with for the LOLZ

On the web, there are multiple pages where people sucessfully run it on 2x Quad core's with just a BIOS update, even though it was only designed for 2x Dual Cores..
Ive got a couple of Xeon E5345's spare, which are matching processors, and both quad cores...
But when they are installed.. The computer freezes under load...
Regardless of wether i try a video render test, or CPU performance test..

A few people have said "perhaps your particular computer is unable to run quad cores.. But surely, if a motherboard wasnt able to run a certain processor, it wouldnt POST at all???

The computer boots perfectly on the 2x quad core's, gets to desktop fine.. Just as soon as you put load on it, it freezes then restarts my computer..

I first thought that perhaps its the power supply not being strong enough to power 2x quad core's... But i removed one of the processors, and just ran it on a single Quad core CPU, so that saves like 80w of power that would have been powering the second chip.. But still does it..

The power supply is a 550w Stock HP psu, which normally powers the system fine, which has 2x dual core 5160's, 4x sticks of DDR2 ECC RAM, and a GTX 550Ti graphics card...

cheers

 

[gamerdude1989]

but surely, if a CPU wasnt capable of running in it, it would completely fail to POST altogether?

Like i said, they boot up the computer fine, i can surf the net for hours etc..
Im actually on the HP workstation writing this..
But as soon as you put any proper load on the CPU's, thats when the system gives up