Ken Mays wrote: > > > 2. Executed glxgears > Response: > - Perf Meter goes to 2 (GPU clock: 550 Mhz/ Memory Clock: 999 Mhz) > - glxgears shows: 14.5K FPS for 30 seconds, then drops to 487-550 FPS > afterwards > - Remains in effect until I cancel glxgears session and restart (#2). > - glxgears restarted goes back to 14.5K FPS and then throttles back to > 487-550 FPS after 30 seconds. > -Perf meter continues to show a level of 2 throughout this session (>=180 > seconds). Core temp: 57C, Ambient temp: 47C > > Now when I CANCEL glxgears: the Performance meter drops to level 0. > Restarting glxgears, the perf meter goes to level 2 (highest level). glxgears > always drops > 14.3K-14.6K FPS rating after 30 seconds. > > Geez, this IS a bug! > I let glxgears run for five minutes on a Quadro FX 4800 (180.11 driver). Neither the frame rate nor the GPU performance settings dropped during that time. Since the performance settings didn't drop on your system either, it is possible this may be CPU power management kicking in. What's in /etc/pm.conf and what are you SBIOS settings for dynamic CPU power management?
glxgears only hits the CPU hard at startup when it builds the display list for the vertex data. The display list is stored on the card so all the CPU does after that is tell the GPU to execute the display list and print a line to the terminal every five seconds. It is possible the CPU being used after startup is small enough to allow CPU PM to kick in.
