Vulkan vs. OpenGL Linux Game CPU Core Scaling

Written by Michael Larabel in Linux Gaming on 26 June 2017 at 08:08 PM EDT. Page 1 of 3. 31 Comments.

After carrying out the P-State/CPUFreq governor comparison with a focus on OpenGL and Vulkan Linux games, next I ran some fresh numbers seeing how well modern OpenGL/Vulkan Linux games are scaling across multiple CPU cores.

For games sporting both a Vulkan and OpenGL renderer, I tested them while adjusting the HT/core count via the motherboard BIOS of the MSI C236A WORKSTATION board used for testing. The CPU was the Intel Xeon E3-1280 v5 and it was tested in its stock configuration of 8 threads (4 cores + HT), 4 cores, 3 cores, 2 cores, and then finally a single CPU core. Each time the various OpenGL/Vulkan Linux games were run with the OpenGL and Vulkan renderers, all automated via the Phoronix Test Suite benchmarking software.

Vulkan vs. OpenGL CPU Core Scaling Linux

The graphics card used for the testing was the Radeon RX 470 while the software stack was made up of Linux 4.10 on Ubuntu 17.04 with Mesa 17.2-dev. The performance governor was used for the benchmarking process.

Vulkan vs. OpenGL CPU Core Scaling Linux

Dota 2 was having troubles running with just one CPU core active and then a freak hang when running with three cores enabled, so this first test is of two, four, and eight threads. The OpenGL results show an increase in performance from two to four threads while the Vulkan performance actually backed off a bit with the higher thread counts. Some thread synchronization issues, perhaps?

Vulkan vs. OpenGL CPU Core Scaling Linux

Dawn of War 3 similarly had a problem running when just one CPU core was active when using the OpenGL renderer: the game just appeared to hang indefinitely at the loading screen. From two to three threads we saw the OpenGL performance increase while the Vulkan performance was flat-lined with the increasing thread count.

Vulkan vs. OpenGL CPU Core Scaling Linux

The Dawn of War 3 results at maximum image quality were similar to with the lower quality preset.


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