Will GSDX update for DX12?

[AdderDee]

Is there any point in spending time implementing DX12 support right now? Or am I thinking of Dolphin again?

[bomblord]

Is there any point in spending time implementing DX12 support right now? Or am I thinking of Dolphin again?

Considering the massive performance gains DX12 offers I personally think it should be at some point.



Top is DX11 bottom is DX12 it significantly reduces rendering time.

However, I'm not the one writing the emulator so they may have more pressing or important matters. There could also be something with how this emulator works that could make these performance gains of no effect.

[Coma]

I don't think it will be massive on PCSX2, but I can be wrong.

[willkuer]

Direct12 will only help those who are bottlenecked by gpu. Most user's aren't. Those who are don't have dx12 compatible gpu's...

OpenCL is a different story though....

[K.F]

Gsdx really needs a rewrite, and dx12 is as good of an excuse as any. And of course it will help.

Direct12 will only help those who are bottlenecked by gpu. Most user's aren't. Those who are don't have dx12 compatible gpu's...

OpenCL is a different story though....

No, Directx 12 and Vulcan are useful when the CPU is the bottleneck since they allows all threads to communicate with the GPU not just a single thread. See here:

https://software.intel.com/en-us/videos/...l-graphics

[NarooN]

What K.F said. What Vulkan/Mantle/D3D12/Metal/et al. do is *cause* the GPU to become the bottleneck by allowing the CPU's to be utilized properly where they can feed the GPU the way they're supposed to. I think something like that would benefit the emulator, but gsdx itself is a mess and would need a rewrite anyway. If Gabest comes back and decides he's up to the challenge and/or it interests him enough, he may try his hand with it.

[willkuer]

I am not that confident about reducing cpu bottlenecks.
It is still all about rendering. Sure you need some cpu instructions to feed the gpu but this load should be comparably small in comparison to the load the emu core (EE, VU, FPU, whatever) puts on the cpu.
Vulkan will help if your gpu could do more but is limited by the cpu. I would interpret that as an gs bottleneck in the rare case where your cpu is really close to it's limit. Then the additional load to send data to the gpu might push your cpu above your limits and causes slowdowns.
Still I would say the load on the cpu is 95% EE and 5% GS(if at all) per pcsx2 process. You could reduce that 5% by some amount but that will only help if your cpu is really close to its limit. At least this is how I understand this emulator.


A complete different story is opencl. If you perform cpu calculations on the gpu it might reduce cpu bottlenecks.

[ssakash]

The GS plugin has to draw the geometry in the same order as how it was received. That ruins almost all of the caching techniques used by modern games because the Graphics Synthesizer and PC GPUs have very different performance bottlenecks. hence, The performance Gain of DX12 on pcsx2 is still not justified.

[K.F]

I am not that confident about reducing cpu bottlenecks.

It is for CPU efficiency:

http://www.anandtech.com/show/8962/the-d...ar-swarm/4

http://www.developer-tech.com/news/2015/...d-fiction/

http://wccftech.com/directx-12-huge-push...nger-xbox/

http://www.pcworld.com/article/2109596/d...uture.html

If you are using dx or opengl, there will be CPU overhead no matter what other work the CPU is doing, so new API's should help. The only way this is not the case, is if the developers left the main thread for gs, and used the other threads for their work, which I really doubt.

I would say the load on the cpu is 95% EE and 5% GS(if at all)

How did you come up with these numbers?

The GS plugin has to draw the geometry in the same order as how it was received. That ruins almost all of the caching techniques used by modern games because the Graphics Synthesizer and PC GPUs have very different performance bottlenecks. hence, The performance Gain of DX12 on pcsx2 is still not justified.

Ok, don't just copy something from here:

http://wiki.pcsx2.net/index.php/Graphics...Dual_Cores

and say it won't help, just because you read the sentence "different bottlenecks". That has nothing to do with dx12.

[ssakash]

Yeah, I remembered reading it from there before. how is this unrelevant to dx12 ? if you still couldn't understand it, I would suggest you to read the whole article you linked earlier. The bottlenecks in native PC games might not be similar to GS since, The bottlenecks are exactly different on Native PC games. DX12 is aimed at preventing bottlenecks on native PC games. c'mon now just think a little bit and you will understand on why it wouldn't have a sure improvement in performance on PCSX2 (still a hypothesis). I'm not interested in spoon feeding.