5800X Cinebench score lowers with PBO enabled

OpenToSuggestions · 20 Feb 2021 at 14:26

Hey all.
My 5800X gets around 5800-5900 on Cinebench R20 multicore.
With PBO enabled (BIOS or AMD Ryzen Master) it lowers to around 5500.

My motherboard is decent for a B450.
I have a water cooling loop, albeit an entry level one.

I tried the Ryzen Master curve editor in the BIOS and I get similar results as with PBO enabled.
My CPU does run very hot and can often hit 90 degrees Celsius.

Any ideas on what could be going wrong?
I've had a good read on here and on other forums without luck.

OpenToSuggestions · 20 Feb 2021 at 17:23

Joxeon said:
Try setting manual PPT 127 TDC 88 EDC 125 then a curve optimiser negative -15 all cores.

Still 5500. I am stumped!

OpenToSuggestions · 20 Feb 2021 at 17:30

Joxeon said:
What are your temps with those settings?

86C.
It takes a few runs to get a good score when stock. It starts at 5500 and after a few runs hits 5900.

OpenToSuggestions · 20 Feb 2021 at 22:13

DoneADougalOnSofa said:
What is your cooling loop, exactly? Is the pump running at full speed, and are the radiator fans working correctly, with adequate airflow?
That's a hot chip...

Tried reseating the cooler?

It is indeed a hot chip.
I have not tried reseating the cooler, but I may need to clean up and re-apply the thermal paste.

The loop is a 2x120mm rad -> CPU -> 1080Ti.
The fans never go above 50% speed, but my overclocked 1080Ti pumps out way more heat when gaming so this should not be a problem.
The pump speed I can definitely increase.

OpenToSuggestions · 20 Feb 2021 at 22:43

After letting things calm down post boot, I get 5900 on stock and also with the settings as per post #2.

OpenToSuggestions · 20 Feb 2021 at 22:55

Joxeon said:
You might want a bigger rad if you're running both the CPU and GPU off 2 120mms.

It is one rad, but has 2x120mm fans

.
It is an end of line aluminium water cooling kit. I can't upgrade the radiator, but if I cannot overclock the 5800X I am not too worried!

OpenToSuggestions · 20 Feb 2021 at 22:58

Joxeon said:
Yeah it's asking a lot for just 1 240mm rad, how's temps while gaming when you have the 1080ti adding some heat?

Perfectly fine.
GPU sits in the 70s.
CPU sits in the 60s.

OpenToSuggestions · 20 Feb 2021 at 23:00

Joxeon said:
Yeah it's asking a lot for just 1 240mm rad, how's temps while gaming when you have the 1080ti adding some heat?

True, but Cinebench R20 does cause the GPU to add any heat.