Program to monitor Power Supply

I am starting to think I may have a power supply issue and none of the programs I use seem to monitor it correctly or the power supply is bad. I have been using TOverclocker (came with my Biostar MB), Speccy, Everest, HWinfo64, HWinfo32 and SpeedFan. None of these give me consistent measurements or measure the voltages wrong from opening the program. Is there a monitor program out there that is very good at measuring power supply voltages. My MB is a Biostar TZ68A+. Thanks in advance for the help.

What symptoms are you having that you think may be related to a PSU issue?

The best way to measure voltages is not with a software program, but rather with a digital multimeter (set to DC volts on the 20V range or automatic) and using a technique called backprobing whereby the probes are inserted into the back of the power connectors so that they make contact with the wires inside. The only software that I would trust on voltage readings is the hardware monitoring in the BIOS (and even then I would take the digital multimeter reading as being the definitive). This is because software that provides this function takes its readings from the on-board sensors and then applies a predetermined offset which gives you the final output reading. Unfortunately, if the incorrect offset is used, it can lead to cases where a voltage is displayed as being out of tolerance whereas the same voltage tested directly is well within the limits.

Certainly, don't stop using these programs if you wish, but remember that the readings that they give should be treated as a guide and that if you have any undue concerns about any of the readings you should confirm (or otherwise) them with a digital multimeter as described above.

Try looking in the BIOS and make sure what is shown there is what you want. Most software programs are only reading from the onboard sensors when and if they exist.

The monitor program TOverclocker measures 12 volts fine until it is under load for a long time, the min will show it got down to 3.6 volts at some point. I would like to try another good HW monitor program to compare. I looked at the Bios and the voltages are fine there and I checked the PS with a PS tester and that is fine too. It is under load that I think the PS is having issues.

Your PSU is from a respectable manufacturer, Corsair, so I wonder if it is actually something else causing the problem. However, we shouldn't totally eliminate it. What model number is it?

It is more likely to be a faulty sensor, or one that is susceptible to changes in temperatures (which would explain why you suspect that you're having these problems under load). Although the BIOS reads its values from sensors, they are not necessarily the same ones that software programs access. However, remember that whilst in the hardware monitoring tab of the BIOS, your system is not under the same load as when the OS is loaded and running.

This is one of those cases where I would definitely recommend the use of a digital multimeter. The voltage reading you quote (3.6V on the 12V line) is simply far too low to allow the computer to remain operating (i.e. I would expect it to cause it to power off). Are you sure this is the 12V line, and not either of the 5V or 3.3V lines?

CORSAIR Enthusiast Series TX750 V2 750W ATX12V v2.31/ EPS12V v2.92 80 PLUS BRONZE Certified Active PFC High Performance Power Supply


I'm not so sure it is the PSU either, but it does bother me that the voltage drops to 3.6 volts under load. I would think if it really did this it would crash the system. I noticed the other day for the first time that all voltages under TOverclocker will show a low Min at some point during load testing under Prime95. The 12 volts had always done this and now I seem to have all voltages doing it. The system does not reboot or crash, but I did have a BSOD the other day and I think it was my O/C, I have removed the O/C for now.

Good call on removing your overclock. One of the first things to do when experiencing problems is to set everything back to stock/standard settings. It just eliminates one of the possible causes. The same thing, by the way, also applies if you are underclocking.

Do you have access to a digital multimeter? If so, monitor your voltages with TOverclocker as before and then, when the voltage reading dips, check it using the back-probing technique I mentioned earlier. Depending on the voltage you want to check, connect the probes as follows:

Positive/Red probe:

12V - Yellow
5V - Red
3.3V - Orange

Negative/Black probe: Black.

Note that it shouldn't matter which particular wire you choose to probe, but if you want to test multiple (or even all) combinations then feel free to do so.

OK, cool I will try that. In the mean time what is the best monitor program you can suggest?

Do not open up your PSU to do any checking. It can kill you even with the power disconnected.
For most if a PSU is faulty throw it out and buy a new one.

You've already tried multiple programs, and they've all given inconsistent results. In that case, the backprobing technique is the one you should use.

Please heed the above warning: NEVER open the PSU itself.

There is NO software that will monitor the PSU directly. There are hardware monitors and VOMs to test power supplies. The DC supply voltages (3.3, 5.0 and 12.0) acceptable to motherboards and processors usually have a +/-5% tolerance. Outside of this range could cause problems so the meter you use must be able to read at least down to 1/10 (.1) volts.

I measured the voltages while idle and they all were good + or - 10%. When I get time I'm going to measure while under load. Thanks for the info Dwarf the pin outs were spot on. I will let you know what I find under load.

I take it you used a digital multimeter for this. It will be interesting to see what the actual voltage is when TOverclocker is reporting a low value as you reported above.

Yes and yes it will. Sorry I did not tell you I have a digital volt meter. I hope the low voltage shows up. It might be too fast for my meter to see it, but I'm going to give it a shot. My PSU has a 5 year warranty and I really would like to verify it.

As has been mentioned above, if your 12V line was indeed falling as low as 3.6V then your system would in all likelihood just abruptly turn off. It doesn't though, which is why I think that there isn't anything wrong with the PSU, rather the on-board sensor(s) is/are faulty.

Don't wait until you get the low voltage reading to connect your meter - you can run the tests with it connected.

I did a two hour load test this morning with IntelBurnTest and FurMark running at the same time. The multimeter stayed between 12.17-12.19 volts the whole time. TOverclocker had a Min of 12.044 and a Max of 12.148. This test was inconclusive and I plan on doing a longer test when I have more time.

Those results look good and stable.

I agree that longer tests are sometimes needed to get problems to manifest themselves (hence the advice you'll often see about allowing Memtest to run overnight).

However, 2hrs is a reasonable period of time for this, and I would be quite happy with the result you got. Should you wish to test further, then you will need to put more load on the 12V line to check if it still remains stable. The two programs you ran are excellent for this, just ensure that you are using the extreme settings in both cases. In addition, if you have a DVD/CD/BD drive, play an audio CD at the same time. Don't worry if the audio is choppy and broken up, you are merely using the drive motor to put a bit more load on the 12V line.

Make sure that you keep an eye on the temperatures, and be prepared to stop the programs if the temperature on either climbs too high.

I ran IntelBurnTest using max memory and FurMark in a window 1024 x 768 (so I could see the other programs). I could make the window a bit larger and add AA, but the thing is with the case door off my video card (HD 6570) is getting pretty warm (hit 88 c). With the door on I have a fan blowing right on the video card. I will run a video on my TV at the sametime next time. Man that should be quite a load!

I ran a much longer test the other day and saw no drop in voltage on the voltmeter, but TOverclocker did show a drop at some point and I did not see the drop on the voltmeter. If the 12 volts is dropping it is dropping faster then I can see it or faster then the digital voltmeter can pick it up or I took my eyes off the voltmeter just long enough not to see it on the voltmeter. Also I played Far Cry 2 for several hours without a restart or shutdown. Then yesterday I was on-line trying to get a item ready for sale on ebay when all the sudden the computer shutoff. I have an UPS on the system, so it was not commercial power. At the time I was not doing anything, I was almost ready to post it on ebay when the computer just shut off without warning. In event viewer all is said was: 'The previous system shutdown was unexpected.' Seems it could be getting worst, what ever the problem is. Any ideas on how to isolate what the exact issue is? Can memory timings also cause this issue?