For some time now, my PC has been freezing periodically - about once every 2 days, the screen looks normal, but mouse, keyboard etc. do not respond and I have to hold the power key in to restart.
By process of elimination, the culprit appears to be the Xeon Phi 3120A card - I just took the card out and ran the PC for a month without a freezing incident.
Put it back in and it froze the same day.
I have tried it in both possible expansion slots - froze with both.
It is not happening when the card is in use, mostly it happens when the PC is idle and I come back and find it frozen, so it is nothing to do with any Xeon Phi activity.
The motherboard is an Asus Z9 PE-D8 WS with 2 Xeon E5-2655 v2 processors.
It has the latest bios.
The OS is Windows 8.1 Pro.
There is also an NVidia NVS295 video card in slot 1.
I have taken all other cards out (part of my process of elimination).
The Xeon Phi works fine (when the system is not frozen).
What can be causing this and what can I do about it?