Big Sur Graphics performance

[Xzing]

Hello I have recently fresh installed Big Sur using opencore (I'm new to OpenCore) following the guide step by step but...
I have seen a weird graphical performance downgrade! Mostly visible when minimizing and really visible when using creative cloud app, also the unigine heaven benchmark have these stutters a lot, the fps says 60 but the output looks like 25 (not through out the whole benchmark) it's weird. the system is fast but the animations feel worse. Is there any way to restore my "gpu" performance. Catalina was amazing it was running perfectly, but this... Also I'm using iMac18,1 smbios.

SPECS :
BOOTLOADER : OpenCore 0.6.3
GPU : RX580
iGPU : intel 4600
CPU : i5-4460
MOTHERBOARD : B-85M D2V
RAM : 10GB 2 SLOT (BOTH USED)

 

[Xzing]

And also my SSD feels slower.

 

[wstrohm]

Did you solve your problem? My system (at left) gives the following results on Heaven and Valley, running Big Sur 11.2.3 (build 20D91), booted with OpenCore 0.6.7:

 

[mitch_de]

This benchmark is really old - years old and only OpenGL - better use new BasemarkGPU 1.2 (Metal!!, also M1 native)!!!
https://www.basemark.com/benchmarks/basemark-gpu/
(Even DL name is with ..BIG SUR, it also runs with Catalina )
Some results from their result database (OS X):
1.2 MEDIUM (2GB VRAM+). MEDIUM also CPU speed related
https://powerboard.basemark.com/top...mputers/macos/default-environment/median/10/1
1.2 HIGH( 4GB VRAM++): HIGH less CPU speed related but works a bit better with 6 or 8 GB VRAM instead of 4 GB
https://powerboard.basemark.com/top...mputers/macos/default-environment/median/10/1

Here MY RX 570 , 4 GB
i7600 no OC, Big Sur
PS: Use Official Tests HIGH, MEDIUM for compare with others. Custom Tests can be configured (Screen size, other options) but are NOT comparable with Official. The Custom Tests have an C before the Result, like C45333.

HIGH



MEDIUM

 

[wstrohm]

Thanks for the info and the link; tried Basemark GPU today. Results (for system on left) are attached below.