More than a year ago I noticed a performance issue in all 3 X3 games. From what I can tell it is the same issue Yggdrasill has. More specifically the framerate is low while the gpu utilization is also low.
Current system specs:
Archlinux: linux kernel version: 4.4.1-2-ARCH x86_64
Mesa 11.1.2
OpenGL renderer string: Gallium 0.4 on AMD TAHITI (DRM 2.43.0, LLVM 3.7.1)
CPU: AMD Phenom II X4 955BE (quadcore at 3.2GHz)
GPU: R9 280X (TAHITI using radeonsi) (3G VRAM)
RAM: 8G
Originally I had the issue with a AMD HD6870 (1G VRAM) on the open-source graphics drivers (BARTS using R600g). Last january I took some measurements with GALLIUM_HUD for the framerate, radeontop for GPU utilization, htop to measure CPU useage and iotop for hdd usage. Then I went in to X3:Albion Prelude and recorded these numbers:
main menu:
fps 20-24
GPU 35-39%
CPU ~114%
HDD usage 0%
new game menu:
fps ~10
GPU 14-18%
CPU ~106%
HDD 0%
new game argon peace keeper idle:
fps 9-13
GPU 4-11%
CPU 104%
HDD 0%
The CPU was mostly single threaded, which I vaguely remember not being the case 1 year ago. Which I suspect is due to improvements in MESA's opengl validation. So in january I also ran the game with the environment variable MESA_DEBUG=1 and LIBGL_DEBUG=1, and logged all terminal output to the file “X3:AP+D.log”. LIBGL_DEBUG didn't provide any interesting results but MESA_DEBUG did.
Output of “grep Mesa: X3:AP+D.log | sort | uniq”:
Mesa: User error: GL_INVALID_ENUM in glMatrixMode(mode)
Mesa: User error: GL_INVALID_OPERATION in glUniform4("_gl_LightSource[2].attenuation"@8 has 3 components, not 4)
2 weeks ago I replaced the HD6870 with a R9 280X, which has almost identical results from the same tests. (I still have the HD6870, but not in the system)
I will send the log files I made for the HD6870 and the R9 280X, via e-mail. If nessecary I can also make traces with apitace (on the HD6870 while tracing the game runs at 1 fps).
Usefull links:
list of environment variables:
http://mesa3d.org/envvars.html
current state of MESA opengl:
https://mesamatrix.net/
radeon specific list of driver related info:
http://www.x.org/wiki/RadeonFeature/
edit:
The steam build runs at max graphics settings with vsync off and automatic quality conrtol off in 1920x1080 windowed mode. (at low graphics settings the framerate and gpu usage are slightly higher)
