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My computer is fairly modest in terms of power consumption:

  • 4 7200 RPM SATA-II hard drives
  • An IDE DVD-writer
  • Four 80mm case fans
  • Two 95mm heatsink fans
  • Intel Core i7-920 2.66 GHz (OC to 3.80GHz)
  • Sapphire (ATI) Radeon HD 5850

I recently took a look at Speedfan's reported voltages, and they seem somewhat alarming:

enter image description here

These voltages are certainly not within the ±5% range. This voltage is constant whether my computer is idle or running programs.

I'm wondering if I have a bad power supply, or if it's just Speedfan reporting incorrect voltages. (Something tells me it may be the latter, as I'm not sure if the system would be able to function with such low voltages). Cheers!

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up vote 4 down vote accepted

It could be that Speedfan is either not reading your sensors properly, or has bad calibration data for your motherboard.

As your computer actually boots and runs, I would suspect that your power supply is at least supplying most of the correct voltages your system needs. One way to check is to reboot your computer and go into the BIOS and look for a section that says "PC Health Check" or "Monitoring" or something similar, and see what the voltages there say. I'd trust those readings over a third party tool any day.

The other option is to go to your motherboard manufacturer and look up your motherboard to see if they provide any monitoring tools for your board.

Otherwise HMonitor is a similar tool to Speedfan...

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Yep, you were right. BIOS said voltages were fine. Thanks so much! – squircle Jul 7 '10 at 18:35
@thepurplepixel As an interesting side note it looks to me that in speedfan your +12V and -12V line measurements are out by a factor of 10. If you multiply them both by 10 you'll see +11.50V (about where a reasonably loaded PSU would be) and -10.9V which is a bit low but is consistent with the few times I've had cause to look at the -12V line on a PSU, it's always measured quite low for me for some reason. – Mokubai Jul 8 '10 at 10:24

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