Question Is there any way to measure the current draw (or power draw) for my CPU?

[Barney-]

I'm guessing I need to cut into one of the wires in one or both of the CPU power connector cables so the ammeter will be in series with the power in. If so, which wire? Does it matter which power connector?

Motivation: I want to put a funky old-school rotary analog ammeter into my build used to display the "activity level" of the CPU. In fact I also want to do the same for the GPU, but one thing at a time! This is purely for asthetic reasons - but I do want the display to somewhat realistically measure CPU activity.

 

[drea.drechsler]

I'm guessing I need to cut into one of the wires in one or both of the CPU power connector cables so the ammeter will be in series with the power in. If so, which wire? Does it matter which power connector?

Motivation: I want to put a funky old-school rotary analog ammeter into my build used to display the "activity level" of the CPU. In fact I also want to do the same for the GPU, but one thing at a time! This is purely for asthetic reasons - but I do want the display to somewhat realistically measure CPU activity.

Instead of putting a meter in series, instead use a clamp-on meter on the wires leading to the 4 or 8 pin CPU power connector. That will be the total power consumption of the CPU including VRM inefficiency but is almost certainly a 100% analogue to CPU activity.

Measuring CPU-only current draw is a bit more difficult as you have to cut some traces (or lift some coil leads perhaps) on the motherboard and solder in a shunt resistor to measure voltage drop across it.

Putting stuff in series is always problematic is that means you're effectively changing the circuit, resulting i skewed readings and possibly degraded performance.

 

[dorsai]

I'm guessing I need to cut into one of the wires in one or both of the CPU power connector cables so the ammeter will be in series with the power in. If so, which wire? Does it matter which power connector?

Motivation: I want to put a funky old-school rotary analog ammeter into my build used to display the "activity level" of the CPU. In fact I also want to do the same for the GPU, but one thing at a time! This is purely for asthetic reasons - but I do want the display to somewhat realistically measure CPU activity.

Would need more info on the analog amp meter to better understand it's input requirements and it's capabilities.

 

[InvalidError]

A clamp-meter like these:
https://en.wikipedia.org/wiki/Current_clamp

You take the yellow wires that go to the ATX12V/EPS12 connector, put them inside the amp-meter jaw and get your reading that way. No cutting/splicing required.

 

[Barney-]

Instead of putting a meter in series, instead use a clamp-on meter on the wires leading to the 4 or 8 pin CPU power connector. That will be the total power consumption of the CPU including VRM inefficiency but is almost certainly a 100% analogue to CPU activity.

Measuring CPU-only current draw is a bit more difficult as you have to cut some traces (or lift some coil leads perhaps) on the motherboard and solder in a shunt resistor to measure voltage drop across it.

Putting stuff in series is always problematic is that means you're effectively changing the circuit, resulting i skewed readings and possibly degraded performance,

I didn't know about current clamps, thought it had to be in series... this is definitely what I need. Thanks.

Not too bothered about a really accurate measurement, as it's mostly aesthetic.