Since Mesa 10.5.5 I am getting a quite bad performance with primusrun on my laptop to make use of the Nvidia card.
I've tested on CS GO and CS 1.6.
On CS GO, I used to have around 130 FPS, now I have around 80-90 FPS with drops below 60 which cause some stutters/mouse lag.
On CS 1.6, I have around 80-90 FPS with the nvidia card and 150+ with the intel card, so there is definitely a problem.
Here is the bug report on primus bug tracker:
Setting PRIMUS_UPLOAD to 1 seem to boost the performance, but not as much as before. Here is what the primus doc says:
"0: autodetect, 1: textures, 2: PBO/glDrawPixels (needs Mesa-10.1+)"
This *may* be related to this commit:
I have a Intel Core i7 4702MQ CPU.
Reverting http://cgit.freedesktop.org/mesa/mesa/commit/?id=536003c11e4cb1172c540932ce3cce06f03bf44e on mesa-git fixes the issue.
*** This bug has been marked as a duplicate of bug 90839 ***