Score:1

Ubuntu 22.04 fan speed / CPU performance too low

co flag

My laptop (Dell Precision 7560, i7-11850H, Ubuntu 22.04, kernel 5.17) really felt sluggish, so I ran Passmark and to my shock the results were abysmal.

Compared to the average, single threaded was only 1769 MOps instead of 3,193 MOps. Further tests reveal that the cpu boosts to ~3.8GHz for the first test, but then falls back to 2.5 GHz for the remaining tests. On the flipside, the fans never really spin up.

What I already tried:

  • Installed latest bios
  • set thermal management to "ultra-performance" in bios.
  • set cpu-governor to 'performance' (sudo cpupower frequency-set --governor performance)
  • set Power Mode to 'performance'

Nothing resolved the issue so far. Any ideas?


Output of turbostat --Summary --show Busy%,Bzy_MHz,IRQ,PkgWatt,PkgTmp,RAMWatt,GFXWatt,CorWatt --interval 15 while running benchmark

Busy%   Bzy_MHz IRQ PkgTmp  PkgWatt CorWatt GFXWatt RAMWatt
2.01    3846    33924   49  8.05    5.66    0.28    0.00
51.37   4294    50477   94  35.66   33.50   0.17    0.00
94.79   2656    63803   62  23.36   20.66   0.00    0.00
79.66   2500    57852   68  24.75   21.84   0.00    0.00
85.72   2500    72991   58  23.59   21.22   0.06    0.00
66.64   2499    47928   69  16.98   14.12   0.00    0.00
Doug Smythies avatar
gn flag
It could be thermal throttling and/or power limit throttling. One way to know is to run turbostat while you do your tests. Suggest: `sudo /home/doug/kernel/linux/tools/power/x86/turbostat/turbostat --Summary --show Busy%,Bzy_MHz,IRQ,PkgWatt,PkgTmp,RAMWatt,GFXWatt,CorWatt --interval 15`
Hyperplane avatar
co flag
@DougSmythies I added results. The temps peak to 100C at the start and then drop to 60-70C. The issue is definitely the fans not spinning up.
Score:2
co flag

A colleague of mine who owns the same model was still on an old BIOS version (1.8.0) and it turns out BIOS 1.12.1 butchered the single thread performance. I ran some tests with multiple BIOS versions (note: one cannot downgrade below 1.10.1):

bios 1.8.0 1.10.1 1.11.0 1.12.1 1.14.0 1.17.1
CPU Mark 22799 21389 21716 16380 16642 15537
Integer Math 82197 80764 82160 81796 82121 82121
Floating Point Math 45573 40331 42812 37724 30572 24844
Prime Numbers 92.5 67.1 68.1 66 78.8 64.9
Sorting 35484 34472 35236 24022 24975 24269
Encryption 15686 15874 16106 10670 10676 10661
Compression 262098 278784 277925 184606 183600 184190
CPU Single Threaded 3253 3294 3289 1773 1770 1769
Physics 1086 722 728 701 1035 717
Extended Instructions (SSE) 15634 16181 16190 11667 11643 11670

One can very easily even hear the difference. With v1.8.0, v.1.10.1 v1.11.0, when running the benchmark the fans spin up a lot, after that they stay whisper quiet and the performance massively drops after the first benchmark (integer math) runs through. Also, the performance for prime numbers and physics behaves weird.


All the tests above are when plugging directly into the 180W charger. When using battery or WD19TBS (130W) I got ~10% less performance. Crucially, the single thread seems to still be strong.

operating mode (bios 1.10.1) charger battery WD19TBS (lid open) WD19TBS (lid closed)
CPU Mark: 21389 19106 19270 18853
Integer Math 80764 66552 70546 68479
Floating Point Math 40331 34789 36843 35464
Prime Numbers 67.1 66.4 60.1 53.1
Sorting 34472 30714 31393 30497
Encryption 15874 14624 15549 15000
Compression 278784 239844 255046 247432
CPU Single Threaded 3294 3294 3110 3264
Physics 722 728 604 625
Extended Instructions (SSE) 16181 13127 14000 13927
The-Duck avatar
cl flag
I have the same issue. Would you say I'd be losing anything by downgrading to pre 1.12.1?
Hyperplane avatar
co flag
@The-Duck Mine seems to be running fine with 1.11.0 You can read detailed change logs on the dell support website. It seems to be mostly security.
The-Duck avatar
cl flag
Thanks for your reply and detailed report, will try and report back if I find any major issues.
Hyperplane avatar
co flag
@The-Duck Did you manage to reproduce the behavior? Is 1.12.1 also the version from which on the issue occurs? Also: does your 7560 happen to have a GPU? Dell support tried to reproduce the issue and say they couldn't reproduce it. The only difference is their machine had a nvidia gpu and mine doesn't.
The-Duck avatar
cl flag
Not at all. Running 1.17.1 I have no single thread performance reduction. I have a few differences from you though. I do have a GPU and I am running Windows 10 (wouldn't expect this to effect Passmark CPU performance though). Personally, my issue is straight up over heating and the associated performance reduction due to it. I believe Dell's CPU/GPU active cooling is completely broken. My fans are barely if at all audible. (I checked, they are working fine separately). Will try have them swap the HW and see if that resolves anything. Might be a faulty temperature sensor.
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