Maximum CPU frequency reported wrong by lscpu, CPU not boosting to actual maximum frequency

Question

I'm using Ubuntu 20.04, and my CPU model is the Intel i7-10750H:

> lscpu
Model name:                      Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz
Stepping:                        2
Frequency boost:                 enabled
CPU MHz:                         800.000
CPU max MHz:                     2601.0000
CPU min MHz:                     800.0000

This processor has a maximum frequency of 5 GHz, not 2.6. The frequency never exceeds 2.6 GHz, even when playing graphics-intensive games. The stuttering is noticeable.

On my other laptop, with the same Ubuntu version, the boosting mode worked out of the box. How can I un-lame my lame computer?

Update

cat /sys/devices/system/cpu/cpufreq/boost returns 1, so turbo boost should be enabled.

cpupower frequency-set --max 5000Mhz has no effect.

Update 2

Setting GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=force", updating grub and rebooting now shows

Model name:                      Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz
Stepping:                        2
CPU MHz:                         2600.000
CPU max MHz:                     5000.0000
CPU min MHz:                     800.0000

with CPU freq often stuck at 2600 MHz.

And here's a little test, showing that it never reaches the 5000 MHz:

> stress -t 30 -c 20 -i 20 -m 20 &
                        while true

                            lscpu | grep "CPU MHz:"

                            sleep 2
                        end
stress: info: [2900] dispatching hogs: 20 cpu, 20 io, 20 vm, 0 hdd
CPU MHz:                         1506.625
CPU MHz:                         3499.999
CPU MHz:                         3599.998
CPU MHz:                         3511.052
CPU MHz:                         3599.481
CPU MHz:                         3574.137
CPU MHz:                         3505.161
CPU MHz:                         3532.195
CPU MHz:                         3579.484
CPU MHz:                         3578.953
CPU MHz:                         3500.001
CPU MHz:                         3500.000
CPU MHz:                         3591.847
CPU MHz:                         3544.761
CPU MHz:                         3500.000
stress: info: [2900] successful run completed in 31s
CPU MHz:                         2600.000
CPU MHz:                         2600.000
                                  

Answer 1

First up, confirm your turbo is on. It can be disabled in bios, it can be disabled (though temporarily) by programs like powertop, auto-cpufreq, and will automatically throttle out of boost entirely on most laptops set on powersave in the cpu governor.

The bad news is that the manufacturers lie often on the clocks you're going to get. I can't speak to the veracity of the cpupower program or it's function, but I can show you how some of this works so you understand whether you have a problem or not. The spec of the cpu might say you get 5Ghz the power limit on the computer might prohibit that speed. For example: (my lscpu)

Vendor ID:               GenuineIntel
  Model name:            Intel(R) Core(TM) i5-10300H CPU @ 2.50GHz
    CPU family:          6
    Model:               165
    Thread(s) per core:  2
    Core(s) per socket:  4
    Socket(s):           1
    Stepping:            2
    CPU max MHz:         4500.0000
    CPU min MHz:         800.0000

This processor has never run faster than 4.2GHz in this machine because it's a laptop and it just isn't getting the juice/cooling. Many other computers will have similar problems.

Using stress -c 8, from auto-cpufreq --stats:

CPU max frequency: 4500 MHz
CPU min frequency: 800 MHz

Core    Usage   Temperature Frequency
CPU0:   100.0%     77 °C     4200 MHz
CPU1:   100.0%     70 °C     4200 MHz
CPU2:   100.0%     75 °C     4200 MHz
CPU3:   100.0%     71 °C     4200 MHz
CPU4:   100.0%     77 °C     4200 MHz
CPU5:   100.0%     70 °C     4200 MHz
CPU6:   100.0%     75 °C     4200 MHz
CPU7:   100.0%     71 °C     4200 MHz

Obviously, it's not hitting the 4.5Ghz spec max ever in the raw... But, now for the kicker... Most of these processors are rated only for x number of cores to run at full speed (4.5 GHZ, this one is rated to do so only at 4 cores)... Let's try with stress -c 4...

A redo lets us get 4 of our cores going 4292, so that's a bit faster. Let's try with one. Ok, going to 1 thread we hit 4394. That's going to be the limit of the boost on this machine. The fan is barely running when doing these tests and the heat never hits the thermal ceiling here. (Never above 60C).

Anyway, the point was to show you how this works. The problem can be any number of the components that I've mentioned and you literally will have to look at them all.

Answer 2

Perhaps using the package cpupower-gui (https://manpages.ubuntu.com/manpages/impish/man1/cpupower-gui.1.html) might provide a solution. I've had a similar issue in the past and this worked for me.

Answer 3

I was having the same issue, I solved it by enabling Intel Speed Shift in BIOS.