Vulkan performance considerably worse than OpenGL?

[thedevilsjester]

I have recently set up Dolphin on an Ubuntu 17.10 box, and I am having some serious performance issues with the Vulkan back end.

My testing game is Zelda TP, and at 2x Native I can get a fairly stable average ~50 FPS (30 FPS is 100% speed) with the OpenGL back end.

When I switch to Vulkan, performance starts to suffer in a big way:

• Just sitting there doing nothing in the opening area, looking at more or less a static scene, the frame rate jumps around between 19 and 65 FPS.  (its 50+ here on the OpenGL backend).
• Moving the sprite cursor around the screen drops the FPS to 25 until I stop moving it.  (It stays at ~50 on the OpenGL backend).
• Some scenes, like the intro panning past the bridge, drop to 10-15 FPS for a bit.  (They stay at 45+ on the OpenGL backend).
  

I am running 5.0 (ccfeda6).

Is there anything I can do to test if this is an issue with Dolphin's current support of Vulkan, of the state of Vulkan on Linux, or with the drivers for my chipset?

[JonnyH]

What driver are you using for vulkan? What GPU?

I believe the open source vulkan drivers are somewhat experimental and still getting significant changes - it may be that with your particular hardware/software combination you get better performance right now from OpenGL.

It might be worth looking at what versions of the drivers (kernel & mesa) your ubuntu has installed - it may be there are later versions available with improvements already.

[thedevilsjester]

(03-28-2018, 12:21 PM)JonnyH Wrote: What driver are you using for vulkan? What GPU?

I am running an Intel Iris Plus 650
https://en.wikichip.org/wiki/intel/iris_plus_graphics_650

(03-28-2018, 12:21 PM)JonnyH Wrote: I believe the open source vulkan drivers are somewhat experimental and still getting significant changes - it may be that with your particular hardware/software combination you get better performance right now from OpenGL.

I cannot get Windows to recognize a partition to dual boot otherwise I would try and see if I get similar results in Windows or if its just a Linux issue.

(03-28-2018, 12:21 PM)JonnyH Wrote: I believe the open source vulkan drivers are somewhat experimental and still getting significant changes - it may be that with your particular hardware/software combination you get better performance right now from OpenGL.

It might be worth looking at what versions of the drivers (kernel & mesa) your ubuntu has installed - it may be there are later versions available with improvements already.

I just installed the drivers a few hours ago, they are the latest versions; at least the latest versions in the latest stable version of Ubuntu.