PSU Voltage values

Hi, i noticed the voltage ratings on my PSU's were not the expected.

Screenshot at idle

Is it a faulty PSU or a faulty motherboard perhaps. My mobo is Gigabyte ep31 ds3l & PSU - Corsair 450VX. Both are recent buyings.
11 answers Last reply
More about voltage values
  1. Many times the software does not properly interpret the values. Your system would not even work with a 12v rail like that.

    Check the bios under hardware monitor.

    The standard fluctuation allowed by the atx spec is 3.3 and 5 volt +/- 5% and i think +/- 10% for the 12 volt lines(this last one may have been changed to 5 after)

    If you have a good multimeter you man manually measure power at a molex connector. black to red is the 4 volt line yellow to black is 12. 3.3 should not have any issues as it is not used much
  2. It means that the software isn't reading the voltages correctly.
    There's no way your machine would boot up with only 2.11 volts on the +12v rail.
  3. You probably wouldn't be able to boot that PC if the PSU voltages were as bad as reported by CPUID. Are they within specs in the BIOS?
  4. I just checked with the BIOS as you all suggested. it read 11.8xx V and 1.9xx for the DDR2 RAM. I guess its fine since all runs well.

    The only problem im facing however is my p31 board doesn't seem to work with 2x1GB DDR2 800Mhz rams and the system freezes. i took out one of them and all fired up nice and clean. Tried testing both rams with memtest86 and both of them passed. Should i consider getting rid of the 2 sticks and work with only 1 2GB stick for now. Sorry to digress from the original problem. i could greatly use your advise.
  5. What kind of ram? it may need a bit more voltage(if you set tighter timings like 4,4,4,12).
  6. This is the ram. I got 2 sticks of these. I have not overclocked in any way.

    Other specs -

    C2D E8400
    Gigabyte ep31 ds3l
    ATI 4850
  7. nukemaster gave you good advice, measure with a multimeter is the best why to verify readings. As several have pointed out, if the software reading is "in left field" ignore it. Cheap multimeters can be found and are a valuble tool not only for computers but around the house. They are simple and easy to use.

    More inportant is to look at these voltages under load, ie run prime95, or orthos to load cpu and ATI tools 3d view to load +12V
    Might try other software that reports +5/+12V - may get lucky and find one that works.

    Nukemaster, on +5 V I think 4.75 is the bottom limit (5%) as this is the low limit for any TTL ICs ( Most IC in computers are CMOS with a lower limit). My self, I ditch any PSU that alows outputs to vary outside the +/- 3% tolerence UNDER Loaded conditions.
  8. EDIT. damn link did not show up

    That ram should have not special requirements. Strange that 2 would not work.

    Can you check what the memory is running at?

    check the memory tab
    http://www.cpuid.com/cpuz.php
  9. @nukemaster
    When i run 1 stick at a time, all runs clean and smooth. tried running both one at a time and both seemed to work. i downloaded memtest86+ and both of them passed the test.

    @retired_chief
    thanks for the advise sir.
  10. Added
    As nukemaster said, compare your Ram voltage (Looks like 1.94V) to manuf spec. Some require as high as 2.1 V to run properly. Added again as nuke stated, it looks like ram voltage is within spec. No experience with that brand, Also, if running two sticks in daul channel, it is advisable to buy matched pairs (Not a requirement)

    2nd Don't know what your ambient temp is, but if around 75 F then Your CPU MAY be running a little hot. Need to also check core temps under load.
    Note - There have been some problems reading 8xxxx proc temps.
    I would expect a max core temp of in the mid 30s to low 40 at idle

    Added - Run orthos, or prime 95 in windows. My memory checked ok runing memtest but would bomb out within 10 mins runing orthos
  11. ill try that and post the results, thanks for the tips so far.
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