3DMark API Overhead Results: Are API Draw calls the limiting factor for VR performance?

[Voyager]

Been trying to figure out what is a testable indicator of VR performance, and something that one could look at to predict how well it will run, as well as trying to figure out something predictive for how CPUs would perform in IL-2 and other flight sims. I've separately heard that flight sims, in particular tend to be very geometry heavy; we're often looking at scenes bigger than most entire game titles, and that the building of the wire-frame mesh is a CPU function, not a GPU one. I ran the 3DMark API overhead test on my Zen 2 desktop, and my Coffee Lake laptop and got what appear to be interesting results. However, I have not found a way to compare them by CPU on the 3DMark page, so I'm wondering what other people are seeing for their API Overhead test results?

 

Mine are as follows:

 

i7-9750H @4,291 Mhz: 2,167,437 Dx11 Single threaded draw calls per second (http://www.3dmark.com/aot/378274) 1.97 cycles per call

R7 3800X @4,441 Mhz: 2,278,265 Dx11 Single threaded draw calls per second  (http://www.3dmark.com/aot/378472) 1.94 cycles per call

 

It looks like both chips take about two cycles to generate an API draw call, with the Ryzen taking ever so slightly less, so I'm very curious if this pattern holds for Zen 1 chips, 5.3 Ghz I9 chips, and, especially the Ice Lake laptops, if anyone has one they could try it on.

 

If it scales linearly with frequency, that would inply that a 5.3Ghz chip should be able to do ~2.7m draw calls, or about 18% more VR FPS that a Zen 2 chip sees, which I think lines up with the performance delta we seemed to be seeing the last time benchmarking was working in Il-2.

 

Ice Lake numbers will be very interesting to see, because it could be representative of what we may see out of Rocket Lake, which I'm given to understand will be a lower clock frequency than Comet Lake, but in general, a higher IPC, but if we're still getting about 1/2 a draw call per clock, that could imply that the 10900K's would still be the better chip for this genre. 

 

Have other people run this? Have you found similar numbers? 

[SCG_Fenris_Wolf]

I ran it on an i7 7700K OCed to @ 4.9GHz. 

[Jaws2002]

I did this last week. I don't use VR, but one extra result, with different hardware, doesn't hurt.

 

I got my PC running again yesterday. I tried this test a few times.

 

top run:

DirectX 11 Multi-threaded draw calls per second   5 005 310

DirectX 11 Single-threaded draw calls per second  2 423 634

DirectX 12 draw calls per second  32 232 561

Vulkan draw calls per second   33 066 126

 

https://www.3dmark.com/3dm/52377954?