I have Ubuntu 19.04 with all updates installed with Intel i9 9900k processor and Asrock H370M pro4 motherboard, it's updated to the latest bios.
I cannot make Turbo boost work for single thread loads (Which I have plenty of and boost in Ghz would be very helpful) If I run some inherently single thread load (and can confirm that only one core being loaded), for example:
sysbench --threads=1 --time=1000 --test=cpu run
I see all cores jump to 4.7Ghz. I expect the core that is under 100% load should jump to 5.0ghz
I have turbo boost enabled:
$ cat /sys/devices/system/cpu/intel_pstate/no_turbo 0
(if I disable it processor speed won't rise above 3.7)
I've read that sometimes some tools doesn't report accurate frequency and in fact turbo boost may work - I've tried multitude of tools with neither reported any different (all cores maxed at 4.7 doing single thread load).
turbostat for example correctly identifies turboboost parameters:
cpu1: MSR_IA32_POWER_CTL: 0x003c005d (C1E auto-promotion: DISabled) cpu1: MSR_TURBO_RATIO_LIMIT: 0x2f2f2f3030313232 47 * 100.0 = 4700.0 MHz max turbo 8 active cores 47 * 100.0 = 4700.0 MHz max turbo 7 active cores 47 * 100.0 = 4700.0 MHz max turbo 6 active cores 48 * 100.0 = 4800.0 MHz max turbo 5 active cores 48 * 100.0 = 4800.0 MHz max turbo 4 active cores 49 * 100.0 = 4900.0 MHz max turbo 3 active cores 50 * 100.0 = 5000.0 MHz max turbo 2 active cores 50 * 100.0 = 5000.0 MHz max turbo 1 active cores
Still, under single thread load it also shows that all cores are at 4.7Ghz despite only single one is loaded:
$cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq 4815705 4721193 4799105 4772830 4794879 4782198 4891662 4714048 4749921 4737188 4801009 4859085 4734327 4735355 4747906 4826031
There is no setting in bios to make all cores always work at max speed (no core optimization or anything remotely related to cores), I've tried to played with all possible settings with no change.
I've tried to change cpu governor to performance with no effect - only all cores are constantly locked at 4.7 instead of on demand.
What's interesting, if I disable cores with
echo 0 | sudo tee /sys/devices/system/cpu/cpu1/online
and leave only 2 cores online - they do in fact reach 5.0 Ghz but that's definitely not a sustainable solution.
Please advise what can else be done
Thank you in advance!