How accurate is hardware monitoring?

[htmlmasterdave]

How accurate are those readings on the motherboard? Like for example on most boards, if you set vcore to lets say 1.525, you will be get readings which are usually different by up to 5% easily. So is it that the power supply is not supplying the exact voltage the motherboard needs to modify (which is probably true) or, is it that the motherboard isn't modifying the voltage correctly, or that the readings are incorrect? 🙂 My guess is all 3, but it worries because if all 3 are off by a bit in one direction, you could be giving your cpu one heck of a lot of voltage, or not nearly enough... any thoughts?

 

[Twista]

volts fuagawaits? is that how i spells it. Anyway volts can never be always the same and same as cpu speed it jumps up and down.

 

[Mark R]

The monitors are in general not very accurate - the chips usually claim about a 1% accuracy, but this is dependent on additional components which may have a tolerance of 5%. While the 3.3V and Vcore, etc. may be measured directly - the +/- 5 and +/-12V rails usually can't be measured directly by the chip and need external components. The accuracy therefore depends on the quality of the external parts used by the mobo manufacturer - I wouldn't be surprised if 5% parts were the norm.

There are also problems with measuring the CPU core voltage (Vcore) accurately - and the motherboard monitor chips are not equipped to do it. The CPU voltage regulator is equipped to monitor the exact voltage so it can keep the voltage very well regulated. The monitor chips may show a lot more fluctuation than there actually is as well as reading high (although some BIOS and monitor programs may compensate this with a 'fudge factor' to make it look right).

 

[htmlmasterdave]

Originally posted by: Mark R
The monitors are in general not very accurate - the chips usually claim about a 1% accuracy, but this is dependent on additional components which may have a tolerance of 5%. While the 3.3V and Vcore, etc. may be measured directly - the +/- 5 and +/-12V rails usually can't be measured directly by the chip and need external components. The accuracy therefore depends on the quality of the external parts used by the mobo manufacturer - I wouldn't be surprised if 5% parts were the norm.

There are also problems with measuring the CPU core voltage (Vcore) accurately - and the motherboard monitor chips are not equipped to do it. The CPU voltage regulator is equipped to monitor the exact voltage so it can keep the voltage very well regulated. The monitor chips may show a lot more fluctuation than there actually is as well as reading high (although some BIOS and monitor programs may compensate this with a 'fudge factor' to make it look right).

Yeah, I figured they would be relatively useless. I was asking because I'm trying to get my P4 2.4C to hit 3.0. I got it NEARLY stable, but it sometimes crashes after like 20 mins, but I don't want to go to high with the voltage (i was running it at 1.6) The monitor reads it as much lower, like 1.55 when i run it that high.