- Feb 20, 2014
- 53
- 0
- 18,540
Here's the deal:
My main PC has been occasionally (but consistently) crashing or rebooting. Long story short, I strongly suspected the psu, even though it's a top model and fairly new. I checked the voltages with CPUID and Speedfan, and the 12v rail reads very low. ~ 8.9v on one app, and 9.5 on the other.
Well, lots of threads on the internet indicate that you can't really trust these apps to give accurate voltage measurements. I find that extremely hard to believe, (esp since brand new builds always read around 12v) but OK, so I tested my psu with a multimeter, under load:
12.25v, and steady as a rock.
SO HERE'S WHERE I'M AT:
-------------------------------------------
Not only do two DIFFERENT well-respected diagnostic apps show extremely low voltage, but those readings are also fluctuating slightly, as opposed to the direct psu reading that is steady.
I think perhaps all those threads saying not to trust CPUID are a bunch of nonsense, written by kiddies who are just guessing.
The psu itself may be outputiing 12.25v, and so my drives are OK, but the mobo has a voltage regulator circuit, which evidently take the 12v line and changes it to other, needed voltages. I don't yet understand exactly WHAT voltages and where they go, (I'd like to know) but the obvious point is:
If some of that 12v "passes through" the VRC, and remains 12v, BUT THE VRC IS FAULTY, then perhaps THAT'S the voltage being read by the CPUID and Speedfan.
- AND THUS THE PSU IS FINE, BUT THE MOBO HAS VOLTAGE PROBLEMS. ( ! )
----------------------------------------------------------------------------------------------------
I have been searching for days, but can't find any "simple" answers to the following questions:
1: Where exactly does CPUID, Speedfan, etc read the various voltages from?
2: Has either company ever commented on the "low reading" thing?
## 3: Most important: Where exactly on a mobo can one take a 12v reading, with a multimeter, so as to compare it to the 12v coming directly off the psu?
My main PC has been occasionally (but consistently) crashing or rebooting. Long story short, I strongly suspected the psu, even though it's a top model and fairly new. I checked the voltages with CPUID and Speedfan, and the 12v rail reads very low. ~ 8.9v on one app, and 9.5 on the other.
Well, lots of threads on the internet indicate that you can't really trust these apps to give accurate voltage measurements. I find that extremely hard to believe, (esp since brand new builds always read around 12v) but OK, so I tested my psu with a multimeter, under load:
12.25v, and steady as a rock.
SO HERE'S WHERE I'M AT:
-------------------------------------------
Not only do two DIFFERENT well-respected diagnostic apps show extremely low voltage, but those readings are also fluctuating slightly, as opposed to the direct psu reading that is steady.
I think perhaps all those threads saying not to trust CPUID are a bunch of nonsense, written by kiddies who are just guessing.
The psu itself may be outputiing 12.25v, and so my drives are OK, but the mobo has a voltage regulator circuit, which evidently take the 12v line and changes it to other, needed voltages. I don't yet understand exactly WHAT voltages and where they go, (I'd like to know) but the obvious point is:
If some of that 12v "passes through" the VRC, and remains 12v, BUT THE VRC IS FAULTY, then perhaps THAT'S the voltage being read by the CPUID and Speedfan.
- AND THUS THE PSU IS FINE, BUT THE MOBO HAS VOLTAGE PROBLEMS. ( ! )
----------------------------------------------------------------------------------------------------
I have been searching for days, but can't find any "simple" answers to the following questions:
1: Where exactly does CPUID, Speedfan, etc read the various voltages from?
2: Has either company ever commented on the "low reading" thing?
## 3: Most important: Where exactly on a mobo can one take a 12v reading, with a multimeter, so as to compare it to the 12v coming directly off the psu?
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