I think it's a problem with something OSX, but not all the programs. At any rate I get 60k in Big Sur, and 100k in Mojave in Geekbench. Both seem normal. I notice the slow speeds when rendering though, that's what made me look into it.
I've attached the EFI I'm using at the moment. I've kind of lost track of what changes I've made at this point. I've even tried installing other EFIs from people using the same board and GPU, but nothing seems to fix the issue.
guiscard:
There are so very many things different in your EFI from even the core one on this thread, I'm not sure where to suggest you begin... other than start over with the EFI from THIS thread. IOW, almost every category in your config.plist has strange changes and any number of them could be causing you issues. I thought about going about modifying your config for you, but then I realized I really know nothing about your setup, such as what your USB port configuration needs to be, where you cards are located, or what WiFi/BT you are trying to use (based on your config, you seem to be using Intel WiFi).
First, understand I'm only a long-time user, and certainly not a "power user" that understands all of this. All I can do is compare and contrast my various Z390 builds and this one. Some quick things I noticed:
1. You're using the DMAR.aml but don't have the "delete standard DMAR table" in ACPI/delete.
2. In ACPI you have "deletes" and "patches" that to me are either incomplete or misplaced
3. You have a Radeon boost Kext but not the matching aml in ACPI.
4. You have a very different set of Device Properties, including one that looks like it's for an iGPU (which you shouldn't have for iMacPro1,1, and it's got a configuration for a Vega card?
5. You've got the boot arg "igfxfw=2"
6. You've got some Drivers that I've found to cause issues on my machine... really, the only one I guess that I'd remove is OpenUsbKbDxe.efi.
7. Your config is missing the System UUID and System Serial Number -- maybe you deleted them prior to sending (smart).
I've attached a completely different efi (one based on a computer I have) but I've copied over the Platform Info you DID have -- that being MLB and ROM. Please fill out the two "*** fill this out *** fields. Also, this EFI includes the SSDT-UIAC that "I" use... which is SSDT-UIAC-DESIGNARE-Z390-V8, HOWEVER, this version of it has 16 USB port assignments, with a boot flag set to disable one of them to bring it down to 15 (this is to get the on-board Intel wifi card to work on that particular machine and not go over the 15 port assignments -- someday I'll get to fixing that). You'll notice that the Radeon Boost kext and SSDT are based on the Vega 64 (that's b/c on the system I borrowed this from it has a Vega64, but I seem to remember they worked just fine for my VIIs as well). If you'd like to see if the ACTUAL VIIs RB drivers work better, I've zipped that RB folder folder as well where you can get the actual Radeon VII Radeon boost drivers.
Not knowing your system, I can't say this EFI will work from the jump (after you fill out the required fields), but give it a shot, and/or go over it and compare it to yours, and, ideally, the included configs from this thread.
Please report back once you've had a chance to digest/test.
Good luck,
J