I have two Ubuntu boxes, one 16.04 with AMD GPU DRI_PRIME and one 16.10 with AMD APU.

On the dedicated GPU glxgears has a framerate of around 6000 dropping to over 300 when running fullscreen and CSS has 117fps.

On the APU glxgears has always a framerate of 60 and CSS has only 50fps: Why is that glxgears does not scale?

  • 1
    I do not know what is AMD GPU DRI_PRIME. But glxgears is showing 60 fps because vertical sync is on. It is normal.
    – Pilot6
    Commented Feb 4, 2017 at 14:44
  • thanks vblank_mode=0 glxgears is doing the trick: 3200 fps and over 300 fps in fullscreen. BTW: DRI_PRIME is the environment variable that activates my hybrid notebook GPU for more speed! The better benchmark seems to be CSS, though.
    – Leder
    Commented Feb 4, 2017 at 14:57

1 Answer 1


Thanks to @Pilot6: vertical sync was on and is disabled for AMD APU with command: vblank_mode=0 glxgears

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