Testing The Open-Source "RADV" Radeon Vulkan Driver vs. AMDGPU-PRO

Dota 2

Using Linux 4.8 + David Airlie's Mesa semi-interesting branch as of Monday + LLVM 4.0 SVN, the Dota 2 experience was relatively pleasant. Rendering seemed spot-on and there was just one issue when getting things started: fullscreen support.

When trying Dota 2 with fullscreen mode at various resolutions, the screen basically appeared locked and wouldn't update past the loading screen. But when alt-tabbing out of the game, a few new frames of the game's demo would proceed to appear... Alt-tabbing again, a few more frames. Or if leaving the game minimized so it would be off-screen, the demo would complete but would get just a few frames per second.

I tried enabling/disabling the Steam overlay, switching between the AMDGPU and modesetting DDX drivers, switching from Compiz/Unity to Xfce with/without compositing, and other steps to try to figure out why the screen wouldn't update in the full-screen mode. But the easiest approach for now was just running Dota 2 in windowed mode. When in windowed mode, there were no issues.

Thus for this article all of the tests happened in Dota 2 windowed mode for both OpenGL and Vulkan.

Vulkan (And OpenGL) Benchmarks:

For this testing I ran some windowed Dota 2 benchmarks at 800x600, 1920x1080, and 3840x2160 with both the OpenGL and Vulkan back-ends. The cards tested were the Radeon R9 285 Tonga, R9 Fury Fiji, and RX 480 Polaris. All of these tests happened both on the Mesa/RADV driver stack of Linux 4.8 + Mesa semi-interesting as of 29 August and then the AMDGPU-PRO 16.30 driver.

In addition to looking at the raw results, the CPU utilization was also compared between these different environments. With the Phoronix Test Suite it was as easy as setting the MONITOR=cpu.usage environment variable prior to the fully-automated, reproducible benchmarking process.

During the testing process I kept an eye on the 4K display and didn't notice any rendering issues with either AMDGPU-PRO Vulkan or RADV with any of the cards tested.