i5 8600k doesnt go above 4.09Ghz

[pharahuser]

I've ran benchmarks like cinebench and the cpu will go to 100% at 4.09 without turbo boosting to the 4.3Ghz as it should. Is there some settings in my motherboard that might be limitting this? Is something wrong with the cpu?

 

[DRagor]

Maximum frequency in Turbo Boost depends on number of cores that are being used - the more used the lower the frequency. Run a test that uses only one core if you want to see your CPU reaching its max speed.

 

[geofelt]

Turbo boost happens on a single core when the other cores are not heavily used and the temperatures permit.
If you have a Z370 based motherboard, overclock by raising the all core multiplier to a higher number.
You should be able to see 4.6-5.0 on all cores, depending on the quality of your chip.

If you do not have a Z370 motherboard, you are essentially as good as you can get.

 

[pharahuser]

Turbo boost happens on a single core when the other cores are not heavily used and the temperatures permit.
If you have a Z370 based motherboard, overclock by raising the all core multiplier to a higher number.
You should be able to see 4.6-5.0 on all cores, depending on the quality of your chip.

If you do not have a Z370 motherboard, you are essentially as good as you can get.

I'm using a z370 motherboard. How do I change for all cores?

 

[geofelt]

Turbo boost happens on a single core when the other cores are not heavily used and the temperatures permit.
If you have a Z370 based motherboard, overclock by raising the all core multiplier to a higher number.
You should be able to see 4.6-5.0 on all cores, depending on the quality of your chip.

If you do not have a Z370 motherboard, you are essentially as good as you can get.

I'm using a z370 motherboard. How do I change for all cores?

In the bios, there will be an option to set the multiplier for all cores.
It may be in the advanced options on your bios menu.
Just gradually increase the multiplier, leaving all voltage settings on auto.
Stress test and monitor temperatures and vcore.
Use cpu-Z to monitor vcore.
up to 1.3v is safe, the max should be around 1.4v. Stress test temperatures are ok up to 85c.

 

[gingerrankin]

Max turbo boost is 4.1 gzh for 5-6 cores 4.2 for 2-4 cores and 4.3 for 1 cores. In real world never run only 1 core.