Seemingly random CPU downclocking while recording with Streamlabs OBS

[NoPoison]

Hello everybody,

 

I am using Streamlabs OBS to record videos and noticed some weird behavior with my CPU...

It seemingly downclocks randomly on all cores at random times. It downclocks too 3.9 Ghz from 4.7 Ghz... 

This actually causes drops in framerate.

I can also force more aggressive downclocking while running Cinebench R20 at the same.

You can also hear the fans ramp up and down as the clockspeed alternates...

 

PC:

- Intel i7-7820x OC'd to 4.7 Ghz (worst buy in my lifetime btw and gets replaced as soon as zen 3 hits )

- Asus X299 Prime Deluxe

- PSU Corsair sth. 850W

 

Baseline:

- Encoding with x264 or NVENC doesn't make a difference to this behavior

- AVX Offset set both to 0 (tried -1 on both doesn't make it better as well)

- CPU Temperatures not above 65°C

- VRM Temperatures seem ok also but I am not sure where to look and if these numbers are correct in HWInfo 

- Windows Energy plan is at maximum performance

- Clocks stay consistent in Cinebench, Prime95, Realbench and all other Games and Programs I use

- I also tried disabling C/P-States, Intel SpeedStep and so forth..

- Adding voltage/ decreasing clocks doesn't affect it too

- I also looked at Intel Extreme Tuning Utility, because it gives a hint to what is throttling. It reports: NO Current limiting, thermal throttling, power limiting...

  tho' I have CPU SVID not enabled? maybe it doesn't report it correctly then?

 

I am pretty unsure of what is causing this...

Does any of you have an idea?

Do you know another good program that's using AVX Instructions so I can validate on that end?

I know OBS is using AVX.

 

I am thankful for any input you give me!

Thanks alot

Florian

 

 

 

 

 

 

 

 

[Tom_nerd]

what are the CPU temps while using OBS

[NoPoison]

around 50 degrees, see:

 

[Tom_nerd]

what cooler are you using?

[NoPoison]

I am using a Fractal Design Celsius S36 with 3 fans pulling and 3 fans pushing in the front of my case.

Pump is ok. I am controlling the fanspeed with AI Suite 3 to keep it somewhat quiet...

 

[NoPoison]

I found the solution for my problem.

It seems as altough I set the AVX Offset to 0.

My CPU would use the old Offset.

After updating the BIOS to 3105, loading optimized defaults and reloading my OC Profile.

Everything works now.