How does CPU influence VR when high resolution gaming is GPU bound?

[wunkley]

As title.
Can anyone provide personal experience with data to back it up or provide me with good links please?

I'm genuinely confused regarding VR performance with regards to the CPU. As I understood it, and as any benchmark review has shown for years, once you get to 4k 60Hz gaming the GPU is always the 'bottleneck' and there is minimal difference in FPS and performance between an old but decent overclocked 6 core 12 thread CPU (like my 5930k) and a modern 6 core 12 thread CPU.

The reverb G2 is essentially almost x2 4k resolution, so how can a CPU upgrade have any meaningful impact on performance when a game must be GPU bound at such high resolution? People seem to say that VR is different and a CPU upgrade would help. How when ultra high res gaming is entirely GPU bound?

I'm currently on a 5 year old intel i7 5930k overclocked to a v decent 4.6Ghz, with a 3090FE. VR performance on the G2 in Flight Sim 2020 has given me the upgrade itch.

And specifically, For VR in Flight Sim 2020, would there be any point upgrading from my current CPU to an intel 11400 for example? All the CPU benchmark comparisons I see are only ever at 1080p or 1440p max. This tells me nothing for gaming at 4k or VR higher res....

 

[wunkley]

Because you are rendering the scene from two different view ports. That means the work done by the CPU (often bound to a single thread for rendering) is up to double as it has to handle twice the amount of draw calls, culling etc, and in preparing the command lists before dispatching everything off to the GPU for rendering to the displays in your headset. There are vendor specific features, such as single pass stereo from Nvidia, which seek to reduce the work required by the CPU in drawing the scene twice but as you can imagine implementation is not universal and it requires specific models of GPU.

Thanks! Just the kind of answer I was looking for.

For VR specifically then, would you know or be able to reason out how my current oldish 6c/12thr 5930k at 4.6Ghz might compare to a 6c/12thr intel 11400 (seems an amazing budget option) or perhaps an 8c/16thr 10700k in Flight Sim 2020 in VR specifically? Would either help to bolster up the minimum FPS? If so by what amount? I'm looking for significant gains to consider the expense and hassle of a motherboard and cpu upgrade....