Regularly hitting 11.7V on the 12V rail under load (HWMonitor)

[Christopher Bohling]

So, I recently posted a thread where I discussed the need to upgrade my GTX 970 because it seemed to be dying (driver crashes, nasty hitches, running hotter than it should) I cleaned it but that didn't solve anything, so I decided to just say what the hell and buy a new GPU. Multiple people suggested testing the power supply as well to make sure it wasn't the PSU going bad, but I recklessly ignored that advice and just bought a GTX 1080 instead, because lol.

Turns out that the GPU was actually (mostly) the problem and my 1080 is running perfectly. I'm running it with a Ryzen 7 1700 at 3.8 Ghz on a Seasonic M12II 520 EVO (which I know is an older model. I've had it for about 2 years.)

Then, I got paranoid and decided to check power supply voltage ripple using HWMonitor while under heavy load (Prime95 + Superposition) and noticed that in the heaviest load situations, the 12V rail dips down to about 11.7V, which AFAIK is outside the 120mV ATX specifications for good/safe/whatever.

So, I guess my questions are:

1. Is the dip to 11.7V enough to cause problems? (Bearing in mind I have not noticed any problems. My hardware seems to perform perfectly.)

2. Is HWMonitor full of crap about this?

I have enough money that replacing the PSU is not really a problem if I need to do it, it's just a hassle.

 

[UsandThem]

Software programs that read PSU outputs aren't always accurate, especially with newer chipsets like AMD. There have been many people come here and ask about their readings in programs like HWMonitor.

You can be sure by using a PSU tester and get the readings, or take a look in your BIOS at the power readings. If you have a good PSU, the 12v shouldn't fluctuate that much and should be pretty steady.

 

[Christopher Bohling]

Software programs that read PSU outputs aren't always accurate, especially with newer chipsets like AMD. There have been many people come here and ask about their readings in programs like HWMonitor.

You can be sure by using a PSU tester and get the readings, or take a look in your BIOS at the power readings. If you have a good PSU, the 12v shouldn't fluctuate that much and should be pretty steady.

If I'm looking at the BIOS (and therefore not under load) what sort of readings on the 12V rail should I consider worrisome?

 

[UsandThem]

If I'm looking at the BIOS (and therefore not under load) what sort of readings on the 12V rail should I consider worrisome?

It depends what ATX version your PSU is, but for version ATX 2.2 it is 11.40 to 12.6.

https://www.lifewire.com/power-supply-voltage-tolerances-2624583

 

[Rifter]

Test actual voltage, with a multi meter or PS tester. Dont reply on software.

 

[Torn Mind]

120mV is the ripple spec for ATX. Voltage spec is 12V +/- 5%, which is as already mentioned, 11.4 to 12.6 volts. Testing with a multimeter is merely plugging one of the multimeter leads into the black wire hole and the other into the yellow wire hole on a Molex connector .

 

[FaaR]

Then, I got paranoid and decided to check power supply voltage ripple using HWMonitor

Voltage ripple takes place on millisecond timescales. You need a fast digital oscilloscope to capture it; HWM, as awesome as it is, won't be able to detect it. What you're seeing likely has a technical name as well, I'd call it voltage sag, perhaps...