Tips for getting more performance with linux port

[Koylio 8]

I did some experimenting with linux client, and wanted to share what I found out.

 

I started with a benchmark result of 40fps on i5-4690K and Radeon 390 with open source driver. First test was to try AMDgpu kernel driver instead of radeon, as some performance increase was reported with it. Unfortunetly for A3, I didn't see an improvement with FPS, but another benchmark benefitted slighly with it. Long story short, I ended up with radeon and DRI3 enabled, witch gave me the same results and less tearing than DRI2.

 

Arma seemed CPU-limited, so that was on the agenda next. Changing the governor from ondemand to performance showed an increase of ~3fps. Changing the CPU frequency scaling driver from acpi to pstate allowed the CPU to rise frequency to 3.9GHz, and and performance was increased to ~45fps. Selected governor didn't seem to matter anymore. Patching the kernel with BFS scheduler gave an another boost of ~2fps. Some other kernel optimizations (CONFIG_CC_STACKPROTECTOR_NONE, CONFIG_JUMP_LABEL, CONFIG_CC_OPTIMIZE_FOR_SIZE) had barely effect.

 

Compiling mesa with more optimizations after -march=native -O2 decreased performance, and disabling steam runtime and using the --eon_disable_catalyst_workaround switch didn't improve anyting. Either did running steam in big picture mode without desktop. New si-scheduler in mesa did show improvement in other benchmarks, and seemed to help A3 run more smoothly, but didn't show an increase in fps.

 

In the end I had an average of 48,5fps of two runs. With W7 I had average of 47fps, but it was a more recent version of A3. Improvement also showed in Arma 2 with wine, performance is now on par with windows.

 

Hope you find these results interesting. What I still want to try is experiment with kernel timer frequency and scheduler.

[Koylio 8]

If you have an AMD gpu and are running mesa drivers, you might want to update to latest git-version. Git-3f10067 gave me a nice increase to 50,7fps (average of three runs of Arma 3 benchmark v.0.51 Stratis) from 48,3fps with git-3fb4a9b from last week.