All games only using Core 0 by default (causing stuttering)

Hello,

A strange issue appeared out of nowhere on my laptop.
I am using Windows 10 and my CPU is a I7-6700-HQ

It appears that whenever I run a game, the core 0 always works at 100% capacity, causing stuttering in the game (probably due to clogging), when the other cores are not used that much (general CPU usage around 20% in the last test).

The strange part is:
When I go to the task manager and go to details>set affinity for this game, it shows that all cores are allowed, and if I validate (without changing any option, still allowing all cores to be used), then the CPU repartition goes back to something expected and the stuttering stops.


Any idea of what is happening and how to fix it ? This has been tested on several games (namely For Honor and Tales of Berseria) with the same results, when said games were working fine 3 days ago.
I didn't touch any configuration or option regarding CPU usage prior to the problem happening.

Try setting the power plan to High Performance mode.

RoasterMen said:

Try setting the power plan to High Performance mode.

Plan was already on high performance. I also tried other plans for troubleshooting purposes with the same results

BugMeister said:

- applies to Win10 also..

Thanks for the reply, but I am not certain that you understood my problem.

All my cores are obviously enabled on startup.
The issue occurs when launching a game (that only use one core, some other programs using other cores), and it gets solved whenever I reset the affinity of said game in the task manager (the game starts to use all cores again).

If my cores were disabled in msconfig, Windows wouldn't boot them and I wouldn't even be able to see them at all.