Windows vs Linux idle power consumption

I did a test with a power meter for my desktop PC (7700k at 4.9 GHz):

  • EnOS (KDE) idle after boot - 55W
  • Windows 10 “idle” after boot - 190W (!)

Note that I did wait for Windows to calm down after booting up, it took a while going down from 220W to 190W where it seems to have stabilized. Now I’m back in EnOS and with Brave open (60 open tabs) the system consumes 62W :slight_smile:

Is it normal for Windows to have such much crap running while “idle”? I only use it for gaming but closed down all apps like Steam / Geforce Experience / Windows Update etc for this test. Besides this, a clean W10 install.

There was no indication of any activity in the Task Manager?

Nothing that was an obvious CPU-hog, mostly various processes consuming 1-2% CPU, but let me do another test to get some more details.

The 150 Watt difference have to go somewhere, and depending on the system this could be considered full CPU and/or GPU load. A few Watt difference are fine, but that’s a lot.

Indeed, the power must go somewhere… Did the following:

  • Back in W10, completed all Windows updates, rebooted
  • Quit Steam/Epic/Geforce and some other junk
  • Waited 5 min, very low activity in Task Manager (see screenshots below)
  • No GPU activity as far as I can see
  • Still consuming 188W at the power socket…

Under Windows, what’s the “power plan”? I think it’s Balanced by default, but if it’s set to High Performance this could be forcing the CPU to idle at high frequencies (and consumes more power).

Under Linux, the CPU governor is either “power save” or “performance”. On my Intel i7-9700, it’s powersave by default.

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Interesting, it’s on “High Performance” in Windows and I just noticed that the CPU is not clocking down at idle…

Edit: In EnOS is ticking on at 4.2 GHz consuming only 60W
image

Running Blender in EnOS with CPU render, the CPU runs at 4.9 GHz as expected, total power draw is now 180-190W. So, it looks like the 190W in Windows is indeed indicative of a full CPU load…

image

I love that idea. Do nothing but do it fast. :laughing:

That looks more like GPU is drawing all the power. 7700k is rated around 90W. Or did you mess with overclocking under windows that somehow stuck the CPU in permanent turbo state? It may be disabled under linux.
What is the temperature on the CPU and is the CPU fan running at higher speed (noise) compared to linux boot? This double power should go somewhere and the generated heat should be visible.

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I did a quick sanity test on my desktop (Haswell i7): ca. 60 Watt idle (Linux: schedutil/Windows: balanced) and a few Watt more in performance-mode.

That’s essentially what I would expect.

see this for explanations
https://www.phoronix.com/scan.php?page=article&item=intel-11900k-pstate&num=1

it come from intel witheit their AVX2 512
and thiw will go after running 4,9ghz

*TDW is mesuring at 3,5ghz
so it will required more power ( 30 to 40% )

this is called fried cpu , how long that can works

From the pictures above the RTX 3090 (:muscle: :drooling_face:) is idling at comfortable 46 ºC. :man_shrugging:

Doesn’t make much sense so far.

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Found the issue! It was the 3090 joyfully consuming 110W of power just displaying the Windows desktop… After installing the newest driver using Geforce Experience (with option “clean install” to reset nVidia settings to default), it dropped to 15W in idle. Total power in Windows is now a more acceptable 80W. This is also in alignment what “nvtop” reports (15-25W):

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I saw that older driver version in the Task Manager picture, but since the temp and graphs were all down … Well, the more you know.

Nice that you figured it out. :+1:

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By the way, the reason I checked the the total power draw of the machine is that I’m about to upgrade from the 7700k (OC to 4.9 GHz) to a Ryzen 5900x. Max power draw today is about 480W-500W and I have a 750W PSU (older Corsair AX750). I wonder how much this will increase with the 5900x and if the PSU will manage…

Just goes to show you what crappy drivers do. The 5900X is 105W like my 3800X i think. I guess you are planning on pairing it up with the 3090. I still think you’ll be fine with the 750 watt. Processor is only 14 watt difference.

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Yes, I will run it with the 3090. I will keep the PSU, it should be fine.

The Ryzen should be somewhat more demanding. Personally I would be fine with the 750 Watt PSU.

There are calculators like https://www.bequiet.com/en/psucalculator but depending on the source they may have an interest to up-sell you (OMG the theoretically spike max. draw, buy our amazing 1k Watt PSU). I would go there, check my current system against what they say and put that into relation with the new parts.

Was hardware compositing enabled in EnOS? My only thought is that there’s hardware acceleration going on in one platform and not on the other. If that’s not the case, it’s an astounding difference.

Yes.
It’s very busy profiling you

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