Inexplicable voltage and temperature spikes and drops on P8P67 Pro

[mmaestro]

Hi all. This is a follow on from this thread:
http://forums.anandtech.com/showthread.php?t=2187972
I've been seeing for a couple of weeks weird voltage drops (and occasionally spikes) as well as odd temperatures. The sort of voltages I'm seeing are:
Vcore: 1.34V High, 0.20V Low
VIN1: 1.01V High, 0.01V Low
AVCC: 3.41V High, 0.03V Low
3VCC: 3.39V High, 0.05V Low
VIN4: 1.00V High, 0.01V Low
VIN6: 1.91V High, 0.01V Low
VIN5: 0.01V High, 0.01V Low
in HWMonitor. What usually seems to happen is that I'll have all those readings without the VIN5 reading, and that VIN5 reading will pop up at the same time everything else drops through the floor, only for a fraction of a second. With HWMonitor off, I'm also getting occasional logs on Asus' AISuite of drops (12V down to 2V, for instance) and spikes (VCore up to 2V for a moment, 5V up to 8.5V) and weird temperature drops and spikes (Chipset from 30C to 127C for a fraction of a second, CPU from 35C to -40C). I initially started looking at the PSU, but after adding a UPS with AVR to smooth out our crappy power, and measuring voltages on the PSU directly and then, to be sure, swapping in a different PSU, I'm still seeing the same symptoms. I haven't yet measured any voltages directly on the board, and had a look last night to see if there were any obvious points to measure on. I didn't see any (what there is must be undocumented, unfortunately). This is really weirding me out, any suggestions for what may be going on? I'm completely at a loss.

 

[mjavid]

These are not actual voltage measurements, but come from the software, reading sensors, I believe. Seems our software programs are not fully optimized for P67/Z68 boards as yet. I was getting highly abnormal readings for the +12v and -5v, but when I updated my software to its latest version, the 12v readings became ok and it no longer had the -5v option. I am still getting max temps of 98C on core temp, and this is obviously a wrong reading. My mobo is Asus P 8Z68-V, and the processor is core i5 2500K being cooled by a Hyper 212 plus, with no overclock at present.

 

[mmaestro]

Are you finding the same thing with AISuite? I'd figured that this was a possibility with HWMonitor, but assumed that such kinks would have been worked out at least in Asus' own software. But I get (rarer, but they're still there) weird readings even from AISuite.

 

[john3850]

Your voltages are normal

According to the ATX specification the readings should be between the following values: said by the op

For 3.3V, 3.125 to 3.465
For 5V, 4.75 to 5.25
For 12V, 11.4 to 12.6
Try to only use CPU-Z
Check your voltage at idle and at 100% load

 

[mmaestro]

The problem with using CPU-Z is it doesn't record min/max numbers. The weird voltages I'm seeing are only for a fraction of a second (one of the reasons I'm wondering if it's just bad readings). But I have seen readings outside of those ATC specs: 8.5V on the 5V rail and 2V on the 12V rail. Does CPU-Z even provide readings for those rails? I only saw memory and VCore readings on there.

 

[mmaestro]

FWIW, I just had CPU-Z open and saw the reported VCore drop to 0.150 for a moment while idle. Then back up to its normal idling level of 0.968.