Odd stutter on Vulkan backend

[Mario119]

Hey all,

So for a couple of months now I've been running into this rather annoying issue. Whenever I play a game on the Vulkan backend, I experience some weird stuttering/slowdown in-game approximately 10-20 seconds or so. The weird part is that the games run perfectly fine otherwise. Oddly enough, when the stuttering is happening both Dolphin and RTSS (a hardware monitoring program) report a solid 60FPS, with no frame pacing issues. No matter what game I try, the stuttering happens. My PC is more than powerful enough to handle Dolphin with SSAA and high IR, but just to rule anything out I set the resolution to Native with no enhancements and the stuttering persisted.

I've tried many different builds, and I even deleted Dolphin's config completely and generated a new one. All of my drivers and Windows itself is up to date, and I'm using the latest dev version Dolphin. As I mentioned above this only happens with Vulkan. Every other backend is works as intended. One thing to note is that this only happens on Windows, as I've tried using Dolphin on my Ubuntu install and Vulkan works fine.  I'm not sure what the cause of this problem is, but I think Windows updating itself has something to do with it. I recently factory reset my PC for unrelated reasons and lo and behold, the Vulkan backend worked again... for a few days. One day I turn on my PC and open Dolphin so I can play some Double Dash, and the stutter was back. I later find out that Windows did some sort of update, but it won't tell me what exactly it updated.

I've attached a video of me playing a match of Project M below, which prominently displays said stutter below. You can see the stutter at these timestamps in the video: 0:34, 0:52, 1:08, 1:26, 1:41, 1:59. Also, please excuse my 'amazing' Smash skills 
https://www.youtube.com/watch?v=zFDjK6Yqp1Y&feature=youtu.be

System Specs:
AMD Ryzen 7 2700X @4.2GHz
Nvidia Geforce GTX 1080 Ti
16GB DDR4-2400 RAM
512GB Samsung 960 EVO SSD
1TB WD Black HDD

[Mario119]

Oops, just realized I posted this in the wrong place.... feel free to move it, mods!

[Helios]

Moved to support

[mstreurman]

Isn't this just the problem nVidia has with ubershaders on windows? Where the issue really is only gone at D3D11 and all other backends have some sort of stutter (which is only fixable by nvidia because the issue is in the driver and not in Dolphin?) That said, there is no quality difference between OGL, VK or D3D11 thus also no reason to really use anything else than D3D11 on Windows (except for the edge case where VK is a lot faster, looking at you Hyrule field in tLoZ: TP...)

[Mario119]

(10-23-2018, 01:09 AM)mstreurman Wrote: Isn't this just the problem nVidia has with ubershaders on windows? Where the issue really is only gone at D3D11 and all other backends have some sort of stutter (which is only fixable by nvidia because the issue is in the driver and not in Dolphin?) That said, there is no quality difference between OGL, VK or D3D11 thus also no reason to really use anything else than D3D11 on Windows (except for the edge case where VK is a lot faster, looking at you Hyrule field in tLoZ: TP...)

The same problem happened on my RX 580, so I don't think the issue pertains to Nvidia GPUs exclusively. My bet would be something related to Windows, because everything works fine on my Ubuntu installation. As I stated above, the issue actually stopped cropping up when I factory reset my PC, albeit only for a few days.