[SOLVED] Does hotter CPU imply more power usage?

barnyard80

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Jun 5, 2020
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I have a 3950x cpu. It runs hotter under light loads (though this is subject to the usual caveat of 3950x temps being inaccurate on light loads, and it fluctuates in a 10C range) , such as when the cpu is at 30%.

If I run it at 100%, it tends to run cooler. Probably because the clock speeds drops to around 3800 MHZ.

In such a situation, will my computer be using more power when under light loads? Could I reduce electricity usage by increasing loads to 100%?

I am reading my temp using the sensors command in Ubuntu. I don't have Windows.
 
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Solution
Cores tend to get hot under moderate loads due to aggressive boost behavior pushing single cores well above normal power and all of that power being concentrated in a very small area. Heavier loads where all cores are active at base clock runs cooler because power and the associated heat dissipation is spread over a greater area which makes heat transfer to the heatsink much more efficient.

In terms of actual power draw, having all cores at 100% will usually draw more power than one or two cores at max boost. You can easily verify that by looking at "CPU Package Power" in HWInfo or other similar system monitoring tool.
Higher temperature alone does not imply more power consumption. It just implies that the CPU can't remove heat fast enough. You can have a 65W CPU run really hot if it's using a dinky 50W cooler (I don't know why you'd do this) or relatively cool if you paired it with an AIO water cooler or a 120W cooler.

The thing with Ryzen CPUs is it'll report the hottest part of the CPU. Short bursts of activity due to boosting on a single core will make the CPU temps appear to skyrocket.
 

InvalidError

Titan
Moderator
Cores tend to get hot under moderate loads due to aggressive boost behavior pushing single cores well above normal power and all of that power being concentrated in a very small area. Heavier loads where all cores are active at base clock runs cooler because power and the associated heat dissipation is spread over a greater area which makes heat transfer to the heatsink much more efficient.

In terms of actual power draw, having all cores at 100% will usually draw more power than one or two cores at max boost. You can easily verify that by looking at "CPU Package Power" in HWInfo or other similar system monitoring tool.
 
Solution