Intel stops Turbo Boosting after a while.

[TighterLeak]

Hey friends.

 

I got a 4570s Haswell on my desk,

I just noticed in my Task Manager and Intel Tuning Utility that after the system boots up, typically in 2-3 minutes after startup, the CPU clock settles at 3,19 GHz and never hits higher. That's the Turbo frequency of 4 active cores, however, it never goes higher; with 1-core active, the Turbo should be up to 3,6 GHz. Everything works fine for about 2 minutes, with the multiplier jumping between 8 - 36, after couple minutes 3,19 is the max.

 

My hypothesis is that some of my background tasks, services, or whatever running in the background starts to limit the multiplier after it starts up. The question is how do I find which one it is?

 

It's generously cooled, Gelid Tranquillo keeps the temps under 50 °C all the time. 

[badreg]

This is normal. All core boost clock is 3.2Ghz on your 4570s:

 

https://www3.intel.com/content/www/xr/ar/support/articles/000005647/processors.html

 

Unless there's literally nothing else that is active on your OS, or you manually set the core affinity for a specific process, Windows scheduler will cycle between cores, which means that all cores are basically active at all times.

[TighterLeak]

Thanks badreg,

but even with manual affinity to Core 0 and high priority set, the clock still sits at 3,19. Tested now with Prime 95, one thread.