x58 with Xeon X5670 refuses to POST only after restart, fine after shutdown

[eternalpeace]

I've recently bought a Xeon X5670 to replace my i7 920 for my Gigabyte GA-EX58-UD4P motherboard system (remainder of components below). But with the X5670 in, the system will not POST after a restart including restarting from Windows, restarting using physical button, or even restarting from BIOS. The system will POST just fine and continue to boot normally after a complete shutdown, including from windows or with physical shutdown button.

I've tried clearing CMOS multiple times. Flashing latest BIOS (14p) as well as flashing previous BIOS (14k and 13) without fixing the problem. Finally, I placed my old i7 920 in again and the problem went away. No overclocking and everything at stock voltage and before installing the Xeon, I had flashed newest BIOS and cleared CMOS.

Please note that the Xeon X5670 is not on Gigabyte's official supported list of CPUs for this motherboard (but other westmere-ep cpus are) and people have certainly had trouble with overclocking with this combination but I haven't heard anyone complain of this particular problem. My understanding is that this combination is supposed to POST just fine at stock.

Has anyone seen this before? What's the difference on the hardware level between restart and shutdown? Is there any way to force motherboard to completely shut down with the restart command?

Thanks for any insight!

CPU: i7 920 --> Xeon X5670
Cooler: Noctua NH-U12P
MOBO: Gigabyte GA-EX58-UD4P rev 1.0 BIOS 14p
Memory: OCZ Platinum (3 x 2 GB) DDR3 1600
GPU: Gigabyte GeForce GTX 670
OS: Windows 10

 

[bkiserx7]

I'm just guessing here, but try disabling any FastBoot type stuff in BIOS and try again. If that does not fix, maybe turn off Sleep states.

https://msdn.microsoft.com/en-us/library/windows/desktop/aa373229(v=vs.85).aspx

http://superuser.com/questions/5080...g-down-and-turning-on-vs-restart-in-windows-8

 

[P4spooky]

Double check memory timings or try a different set.

 

[mysticjbyrd]

Disable xmp

 

[wisegeek]

Did you by any chance buy this CPU off ebay which was maybe an ES (Engineering Sample)??

 

[MongGrel]

Is the BIOS updated for the CPU ?

Extra Spicy probably wouldn't matter.

Some old MOBO's just aren't capable, I guess you did flash it.

Got me, have a X5680 on a P6T7 on the main, and a X5650 on a P6T V2 running.

Bad chip maybe ? what it sounds like to me honestly.

 

[VirtualLarry]

This probably isn't relevant to the issue at hand, but my new FM1-platform rig, an A4-3420, and an ECS A55 board, if I overclock it past 112 bus clock (12% OC), then it won't reboot in the BIOS. I have to switch the power off on the PSU and back on again to POST.