Request: Please support MultiGPU rendering for VR (parallel eye rendering)

[dsc106]

I understand SLI is dead, and splitting frame rendering was iffy business - at least in pancake mode. Many do not realize that while SLI is dead, multiGPU is not. SLI was merely a bandaid solution until PCI buses and low level apis could support this natively with no temporary solution of a hardware bridge.

One use case that always worked very well for multiGPU was VR - because rather than splitting rendering of every other frame (like in flat screen rendering) you instead could render in parallel - rendering both eyes simultaneously on separate GPUs, nearly doubling performance. Because VR renders the same image twice, slightly shifted for sterescopic, multiGPU in VR was one of the few truly viable gaming use cases.

Currently Vulkan and DX12 has full support for explicit multi gpu... they have had this for maybe 5 years or so now. If developers want it, they can implement it as they wish. Since DCS uses separate render parsers per eye and builds the frames per eye independently it should be even easier to implement. Some suspect that the pro version of DCS (MCS) already supports this (it uses Mutli-edge which enables multi projection systems).

For VR, parallel rendering for each eye is the way to go. It could double performance for those with deep enough pockets and accelerate the future. Imagine twin next generation RTX cards being able to play DCS, maxed out graphics, on an ultra high res PiMax headset at 90fps or even 120fps. This could be reality for users willing to splash for 2 top tier GPUs.

The tech is here today, and is already mature... can we use it?

Perhaps the reason that developers will not/have not added this feature is fear that if they do, Nvidia or AMD may not answer developer help line questions, or fail to optimize drivers to work with their game, etc. - since such a thing could discourage new card sales (why buy a 4090 when you can get 2 used 3080s second hand?). However, if this idle speculation is indeed the case, perhaps ED could leave the support somewhere in the engine to be easily found and enabled by modders unofficially...

Edited October 23, 2023 by dsc106