I’ve noticed serious stuttering while using OpenGL applications (games in Steam, glxgears, etc). I’ve got a GTX 970 and currently running driver version 351.21. My Samsung monitor has a reported refresh rate of 60 Hz.
With Sync to VBlank and Allow Flipping off, glxgears reports ~13411.539 FPS. There is visible stuttering in the gear movement.
With Sync to VBlank and Allow Flipping on, glxgears reports ~55.785 FPS. The stutter seems even worse than with these settings off.
Screen 0: minimum 8 x 8, current 1920 x 1200, maximum 16384 x 16384 DVI-I-0 disconnected (normal left inverted right x axis y axis) DVI-I-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm 1920x1200 60.0*+ 1600x1200 60.0 1280x1024 75.0 60.0 1280x960 60.0 1152x864 75.0 1024x768 75.0 70.1 60.0 800x600 75.0 72.2 60.3 56.2 640x480 75.0 72.8 59.9
So… If Sync to VBlank is on shouldn’t glxgears and other programs use the 60 Hz refresh rate? Why does it fluctuate be twee 53 FPS and 56 FPS (and is this the reason for the big stutter)?
Not sure if it’s relavant but my Xorg.0.log is flooded with:
[ 1097.080] (--) NVIDIA(GPU-0): [ 1097.110] (--) NVIDIA(GPU-0): Samsung SyncMaster (DFP-0): connected [ 1097.110] (--) NVIDIA(GPU-0): Samsung SyncMaster (DFP-0): Internal TMDS [ 1097.110] (--) NVIDIA(GPU-0): Samsung SyncMaster (DFP-0): 330.0 MHz maximum p ixel clock
nvidia-bug-report.log.gz (182 KB)