CPU voltage goes up and down: motherboard's fault or PSU's fault?

[blurredvision]

I've noticed on my new Epox 9NPA+Ultra board, when monitoring the CPU voltage within Windows, it sometimes go up and down by as much .05 volts. I wouldn't really think this is normal. Is it a problem of the motherboard, or my Aspire 500w 20-pin PSU? Or am I just out of the loop, and it is normal?

TIA

 

[Fresh Daemon]

Test it with a multimeter. Motherboard readings aren't reliable.

For instance, Speedfan/MBM5/whatever claims my 12v rail is at 11.7v. If I hook a multimeter into the 12v line, though, it shows a steady 12.12v.

For another instance, software/BIOS tells me my CPU when run at 1.5v is running at about 1.43v. The multimeter, however, shows a steady 1.50v.

If you don't have a DMM, get one. It'll cost less than $20 and it's invaluable for troubleshooting.

 

[numbest]

20-pin PSU?the 24-pin PSU is better,Epox 9NPA+Ultra is 24-pin.

 

[the cobbler]

totally normal for variations of ~.05v in software reporting

software never reports anything resembling accurate voltages

get a cheap mulitmeter, IMHO

 

[ElTorrente]

I think a lot has to do with the motherboard.

My mobo I had before my current DFI was an ASUS a8n-ali Premium. No matter what software monitoring I looked at, all the voltages would fluctuate constantly. Whether I was using Systool, CPU-Z, or MBM. Once I switched to my DFI, ALL voltages are rock solid and don't move at all - voltage graphs are just straight lines now, instead of jagged like the ASUS was.

 

[Dave Sz]

My DFI fluctuates more than my 9NPA+. It's software related, not mobos fault