Thanks, that gave me enough info to get as close as feasible from Windows 10. I couldn't use -verbose due to a known problem, and this is using the stock 229 64-bit release for Windows.
I have some very specific and important notes to make on these performance tests.
First off, a CPU-only benchmark (4800H as noted before)
C:\Emu\mame-mainline>.\mame.exe -video bgfx -bgfx_backend vulkan -nowindow -bench 90 umk3
Average speed: 862.81% (89 seconds)
As you'd expect, it keeps up just fine. Let's try a benchmark with video. As noted from https://docs.mamedev.org/commandline/commandline-all.html#mame-commandline-bench
we can use most of what -bench actually does without shutting off video performance:
C:\Emu\mame-mainline>mame.exe -video bgfx -bgfx_backend vulkan -nowindow -str 90 -nothrottle -sound none umk3
Average speed: 292.24% (89 seconds)
Let's try turning sound back on, just so we have a clear picture of normalized performance.
C:\Emu\mame-mainline>mame.exe -video bgfx -bgfx_backend vulkan -nowindow -str 90 -nothrottle umk3
Average speed: 291.32% (89 seconds)
Okay, so sound doesn't impact performance much at all. Not unexpected for a modern machine, but still good to be sure that there's not a surprise bottleneck there with the OS and drivers.
I would expect actual performance to be able to hold up to at least 150% on your CPU. Again, these can't be apples to apples since there's an entirely different OS beneath our MAME installs, but this should help you at least have some idea of where to start looking. I may not be able to help you dig too much deeper, but if you provide your own numbers from these same tests, we can probably at least work out where to start looking.