CS:GO server performing "better" when stress-tested?

[probbzy]

Hello!
I recently set up a csgo server on an old machine and it's working surprisingly well. I cleared out core 1 and dedicated it to only the server. I took a note of the var and sv when there are 1/12 players online:

Players: 1/12
Core: 1

Pictures:






Then I started to stresstest cpu 0 (server is on core 1) and got these stats:

Players: 1/12
Core: 1

Pictures:





As you can see my sv and var went down. I though it might be the cpu-frequency that was fluctuating so i forced it to 2.7GHz, but the results was the same.
The server is hosted on an old laptop:

hp elitebook 2560p
Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz
4GB 1333MHz DDR3 RAM

OS: Linux laptop 4.9.0-4-rt-amd64 #1 SMP PREEMPT RT Debian 4.9.65-3+deb9u1 (2017-12-23) x86_64 GNU/Linux
Its plugged into the wall without a battery attached.

I disabled Intel HT in the bios but i could not find any power settings.
The server will never have more than 12/12 players online and I'm pretty sure that it will handle that.




(Sorry for bad English ! I'm from Norway)


EDIT:
Forgot to say that i disable intel_pstate module and enabled the acpi-cpufreq module to control the frequency.

[deadflowr]

Thread moved to Debian