8700k OC, Prime95, Task manager "Says" 100%, but two cores are at 50%

[MrSprint]

So this is driving me nuts, with the cooler temps, i decided to dial my rig back up to 5Ghz (Normally run at 4.8Ghz over the summer), so dialled in a offset of 60 in the Bios, set the Multiplies to 50, and everything else auto

DDR4 is at 3700Mhz (4000Mhz Dims)

Clock Cache thing at 48

whats odd though is that when I run Prime95 FFTs, It maxes all 12 threads, but then very quickly, this happens... 

 

Certain cores seem to back off? Also, If i'm rendering in Adobe and leveraging the iGPU too, I get some funny behaviour where the screen will suffer like a soft crash, and the iGPU will just stop contributing...

 

My suspicion is its perhaps a power issue, but perhaps not the offset, but this is where my knowledge starts to thin  

 

Any and all thoughts welcome

 

Motherboard is an ASRock Fatality i6 Gaming on the latest Bios.

[porina]

You may be running into current or other limits. Suggest using hwinfo64 and see what that reports.

[MrSprint]

ok, so I've downloaded hwinfo64, not used it before, what am i looking for?

 

Thanks

[voiha]

2 minutes ago, MrSprint said:

ok, so I've downloaded hwinfo64, not used it before, what am i looking for?

 

Thanks

You need to tag or quote people in order for them to find your reply easier

@porina

[MrSprint]

1 minute ago, voiha said:

You need to tag or quote people in order for them to find your reply easier

@porina

Sorry, rookie error

[porina]

11 minutes ago, MrSprint said:

ok, so I've downloaded hwinfo64, not used it before, what am i looking for?

On the sensor page, there is a limiting section where it will say yes/no to various things. While it is running, see if any of those are showing as limiting. Note it is normal for some things to show as limiting there when idle.

9 minutes ago, voiha said:

You need to tag or quote people in order for them to find your reply easier

One possible exception, which I used here, is that the person starting the thread usually will have it followed, so it isn't necessarily essential to tag/quote them unless making a specific point.

[MrSprint]

9 minutes ago, porina said:

On the sensor page, there is a limiting section where it will say yes/no to various things. While it is running, see if any of those are showing as limiting. Note it is normal for some things to show as limiting there when idle.

ok, so I think I'm looking in the right place, but with Prime running, none of these appear to change (assuming this is the right view?) 

[porina]

1 hour ago, MrSprint said:

ok, so I think I'm looking in the right place, but with Prime running, none of these appear to change (assuming this is the right view?) 

Scroll further down.

 

There is one more thought, is your system failing Prime95 stress test? Each thread stops running if it encounters and error, but this doesn't explain why the overall CPU still reports 100% if so...

[porina]

This is the section I was referring to. Ones near the top "IA" are core related. Turbo limit and turbo attenuation appear normal when running stock settings and not under load. See if any of the others flip under load.