Power supply and 12 volts, how to measure correctly?
I decided to check my old power supply (some ancient corsair with one 12 volt line) how much it sags under load. The system consists of a Ryzen 5 3600 processor and an AMD RX 6600 graphics card, which has additional power from a 6 + 2 pin block. I borrowed a multimeter from work, ran the FurMark tests for the video card and Aida64 for the processor on the computer at the same time. I waited a few minutes, took a free cable with a 6 + 2 pin block and started measuring. Black probe into the black connector, red probe into the yellow connector. Without load, the device showed 12.1-12.2 volts. Under load from two tests, it also shows 12.1-12.2 volts. Maybe I'm doing something wrong? Is it possible to measure the voltage on a free block at all? I thought it was possible, because in my block there is only one line for 12 volts, which means that all 6 + 2 pin video card power blocks must have the same voltage. But why then there is no voltage drop? The power supply is 550 watts, consumption under load reaches a total of processor + video card in the region of 200 watts. The power supply is over 10 years old.You measure everything correctly. But it doesn’t sag, because the stabilizer is in the PSU, and it works well, 200 watts is not a problem for 500. In general, 10 years ago everything was done much more reliably. I even have an ancient 2001 computer that I use for DOS programs and the oldest games.
Raptor
Raptor wrote:
But why is there no voltage drop then?
A high-quality impulse switch, which is a power supply unit from a computer, should not have voltage drops in the load range of 15-85% of the real power (for cheap ones, real and declared ones usually do not converge).
Raptor wrote:
The power supply is 550 watts, consumption under load reaches a total processor + video card in the region of 200 watts,
which is 36% of the declared power.
Raptor
did everything right :)
By the way, some semi-professional and almost all professional multimeters have a function to display the minimum and maximum measured values. Denoted MAX/MIN . This function allows you to display the minimum and maximum values ​​memorized during the measurement. Relevant when measuring something with a transient. Can be used in resistance, temperature, voltage and current measurement modes. I don't know what kind of multimeter you have, but if it has the aforementioned capability, then you can measure the "peak", so to speak, in terms of power, and in different games. The results are sometimes quite startling.