As of June 2018, what backend is considered the best?

[Silent Hell]

Does anyone else get strange one time stutters with Vulkan. No, not shader compilation. For example, whenever I fire up Dolphin and launch Sonic Colors, I get a weird stutter when I load an act, but only for the first one I load and then never again. If I close and relaunch Dolphin the same thing occurs. It's really weird. I've tested this by loading the same act every time and it's consistent 100% of the time.

[Zonafer]

Have you tried D3D or OGL?

[Silent Hell]

It doesn't occur on D3D, but I only asked if this is a common quirk with Vulkan in general. Other games do stutter more with Vulkan than D3D so I figured Vulkan is just more experimental with the shader cache.

[Zonafer]

Yeah, Vulkan is a bit more unstable compared to the other options. Some games still run better on it, though.

[DaRkL3AD3R]

Vulkan gives me perfect performance under various situations where OpenGL and D3D11 both drop frames. Metroid Prime map screen, Twilight Princess's Hyrule field are just a couple examples. It is not a meme or placebo. We're talking massive performance gaps just from switching to Vulkan. What I'd like to see some technical discussion on from developers, is what exactly about Nvidia's driver is preventing Ubershaders from working properly under OpenGL and Vulkan, how this issue can be rectified on their end, and lastly whether or not talks with Nvidia are being performed by developers from the Dolphin team to work towards getting a driver solution to these problems.

[Kurausukun]

This sounds like a disc loading problem actually--does the situation change if you turn on/off "speed up disc transfer rate"?

[AnyOldName3]

I'm pretty sure the thing with Nvidia's ubershader stuttering is that when you've got a really complicated shader with a few big branches controlled by uniforms, it creates several variants of the shader where different branches are taken in each one. This effectively swaps uniform changes with a big shader to program changes with a smaller shader. If you've not set a uniform to a certain value yet, it sometimes hasn't actually prepared the other shader variant, so still has to compile and optimise it, negating the whole point of having ubershaders.

Assuming this is something I read rather than imagined, Nvidia should really create a program-specific profile for Dolphin where shader variants as an optimisation are disabled.

[JonnyH]

(08-16-2018, 01:00 AM)AnyOldName3 Wrote: I'm pretty sure the thing with Nvidia's ubershader stuttering is that when you've got a really complicated shader with a few big branches controlled by uniforms, it creates several variants of the shader where different branches are taken in each one. This effectively swaps uniform changes with a big shader to program changes with a smaller shader. If you've not set a uniform to a certain value yet, it sometimes hasn't actually prepared the other shader variant, so still has to compile and optimise it, negating the whole point of having ubershaders.

Assuming this is something I read rather than imagined, Nvidia should really create a program-specific profile for Dolphin where shader variants as an optimisation are disabled.

Variants are normally created due to other parts of pipeline state (like blend state, different raster modes may also affect the shader) - less likely to be uniforms.

[SCOTT0852]

Personally, all I've noticed is OpenGL works on old graphics cards where Direct3D fails, but it's slower. I've never tried Vulkan, as my old card didn't support it and D3D works fine on my current one.