primusrun slower than optirun?

[David Schmitz]

Hi,

I just installed primusrun and did a quick check with glxgears it seems 
that primus run is slower than optirun.
How does that come about?

dave at w520:~$ primusrun glxgears
302 frames in 5.0 seconds = 60.370 FPS
298 frames in 5.0 seconds = 59.482 FPS
298 frames in 5.0 seconds = 59.479 FPS
XIO:  fatal IO error 11 (Resource temporarily unavailable) on X server ":0"
       after 1031 requests (1031 known processed) with 0 events remaining.
X Error of failed request:  BadDrawable (invalid Pixmap or Window parameter)
   Major opcode of failed request:  137 (DRI2)
   Minor opcode of failed request:  7 (DRI2GetBuffersWithFormat    )
   Resource id in failed request:  0x2c00002
   Serial number of failed request:  2023
   Current serial number in output stream:  2023
dave at w520:~$ optirun glxgears
3699 frames in 5.0 seconds = 739.615 FPS
3499 frames in 5.0 seconds = 699.667 FPS
[VGL] ERROR: in readback--
[VGL]    246: Window has been deleted by window manager

Regards
David