This gpu runs at 1069mhz at a so called 35w limit, power spikes 45-50w. No matter what setting i try in PBE, adjusting core mem mhz, power watts amps... nothing will actually change even though PBE sees the modified saved bios settings. I think somewhere in the HP mainboard or bios is an external limiter to the funky proprietary 8x pcie connector that this gpu uses. Because of this, even unlocking the shaders will put up nearly the exact same benchmark results, except maybe slightly lower scores with slightly higher temps. I have tried undervolting but nothing changes its 0.900v core voltage, even at idle. there are some fluctuations like 0.863v or 0.913v or whatever, but the card is hard stuck.
Using MSI AB, open, settings, extend official overclock limits, close, restart (never open msi ab again)... this lets AMD Catalyst tuning allow you to play with core mhz and mem mhz. But MSI AB has no control, and further vbios editing via PBE doesn't change anything at all related to watts amps core mem mhz. The hex editor obviously works, but again no real change in performance.
Also this elitedesk is special because it is the official dgpu version with a 150w power brick, unlike other standard 800 g4 or 705 g4 models that only come with a 90w power brick. These dgpu models also only come equipped with an intel "t" 35w variant cpu. Replacing with a non "t" cpu, as i have with a locked i7-8700 will further power limit the dgpu by about 25%. The i7-8700 without gpu load will go to 88w even though technically it is turbo limited to 122w, but performance loss seems negligable. You can use Intel XTU to artificially power limit the cpu to mimick a "t" cpu of 35/45w limit and gain back all the gpu(rx560) performance that is lost (the actual power limit is about 50w/50w before the gpu starts to suffer performance loses. The mainboard(motherboard) clearly is shunted somewhere but i haven't found the interest to find it and it is probably for a good reason.
The only thing i cant figure out is how to undervolt this rx560 as it seems completely locked down to 0.900v. stock clocks, stock overclocked, 1024 unlocked stock, etc, it always hovers around 800-1100mhz under a power virus. Obviously, pulling the voltage down and finding core voltage frequency equilibrium would be the ideal situation.