HD4600 intermittent QE/CI (Big Sur)

[Haggis]

I've set up my first Hackintosh (HP EliteDesk 600 G1 SFF i5-4590) with OpenCore, and it's gone really well, except that the HD4600 only sporadically has Quartz Extreme (QE/CI). When I restart, it seems random to me as to whether it will be good or not. When it's bad, the dock is not transparent etc & Hackintool reports the following:

 

* VDA Decoder: Decoder Failed

 

* Quartz Extreme (QE/CI) No

* Metal Supported No

* Metal Default Device No

* Metal Low Power No

 

Does anyone have any suggestions for what could cause this unpredictable behaviour? `config.plist` attached.

config.plist

[Haggis]

Hi — thanks so much for your time, it's awesome having someone so knowledgeable examining my config.plist

 

I removed stolenmem and fbmem as suggested. Then I tested it with a series of restarts:

 

* after the first restart nothing improved

* I restarted a second time and cleared NVram this time (from the OC boot menu) and this time everything worked perfectly

* I restarted a third time to see if it was still good and unfortunately it had reverted to the bad state

 

So overall the changes don't appear to have helped. As previously, if I restart enough times (3 or 4 usually) without changing anything at all, I eventually get a reboot where the QE/acceleration is working perfectly.

 

Both Lilu (1.5.5) and WhateverGreen (1.5.2) are at the latest versions.

 

I also tried adding "framebuffer-cursormem 00009000" but then the HP wouldn't boot successfully. Eventually I just reverted the config.plist.

 

I'm wondering if perhaps my config is fine, but if something else could be the cause. eg would a flat CMOS battery have any chance of causing this?