CPU overvoltage resetting after sleep on Asus P8Z77

Mark R

Diamond Member
Oct 9, 1999
8,513
14
81
I've got a 3770k on an Asus P8Z77-M.

It works great, clocking up to 4.4 GHz with no problems with temperatures, running Win 8x64 very nicely.

But, there is a serious problem. After waking from sleep mode, the system is very unstable, crashing within a minute. I've traced this to the CPU core voltage. Normally, the BIOS provides a little overvoltage to the CPU, or this can be programmed manually. However, after waking from sleep mode, the CPU voltage reverts to stock, but the clock speeds remain overclocked.

I've been able to prove this at mild overclocks, and using monitoring/testing software, which proves the CPU voltage underload drops by about 0.15V after waking from sleep mode.

Is there any fix for this? Presumably, it would have to be in the BIOS, as the OS won't be able to do much for it.
 

Puppies04

Diamond Member
Apr 25, 2011
5,909
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76
You could check to see if there is a newer bios available however disabling sleep seems like the easiest answer (sorry if that sounds a little patronising).

Edit. BTW your voltage readings could be reporting incorrectly and might be a red herring, are you using a SSD? Certain models really don't like being put to sleep and will become unstable upon wakeup.
 
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tweakboy

Diamond Member
Jan 3, 2010
9,517
2
81
www.hammiestudios.com
Dont use C1E , or speedstep ,,,,, and puppies93 is correct . like my dads a-data 120GB has many issues sometimes it doesnt wake up or you have to reboot cuz OS is bugged out........
 

samboy

Senior member
Aug 17, 2002
217
77
101
I had a similar problem with a P8P67 system and traced this back to the ASUS Ai Charger driver not working correctly when resuming from sleep mode.

I had everything stable and then started to experience this issue after I purchased an iPod touch for my wife. Thought that it was initially iTunes, but downloaded the MS Windows debug symbols and got a crash dump in the Asus Ai Charger drivers. I reported this back to Asus; but don't think they were too interested in the problem.

Anyway, if you do charge Apple devices via USB then removing the Ai Charger driver may be the solution. I never installed them on the P8Z77 board that I later purchased.
 

Mark R

Diamond Member
Oct 9, 1999
8,513
14
81
I do have an SSD, but it's an intel one, and it's never minded sleep before. Besides, the system is *only* unstable if the overclock is too high for stock voltage.

If I reduce the overclock, so that it is stable at stock voltages, things work perfectly waking from sleep.

I think the CPU core voltage is also being reported correctly. If I set a manual CPU overvoltage of 0.1V, and monitor CPU VCore continually, sleep the PC, and wake it, the graph shows a sudden drop of 0.1V at wake up. If I set a manual overvoltage of 0.2V, the graph shows a drop of 0.2V at wake up (giving the same voltage as stock clocks would).

I haven't installed the charger drivers. It's basically a completely clean installation of W8x64 using intel drivers.