Hmm. Interesting. But seems to be false? I just unplugged one of the DVI monitors and it seems to be functioning correctly??
adamm@mira:~$ xrandr --screen 0 Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 VGA-0 disconnected primary (normal left inverted right x axis y axis) HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 708mm x 398mm 1920x1080 60.0*+ 60.0 59.9 30.0 24.0 60.1 60.0 1600x1200 60.0 1360x768 60.0 1280x1024 75.0 60.0 1280x720 60.0 59.9 1024x768 75.0 70.1 60.0 800x600 75.0 72.2 60.3 56.2 720x480 59.9 640x480 75.0 72.8 60.0 59.9 DVI-D-1 disconnected (normal left inverted right x axis y axis) adamm@mira:~$ xrandr --screen 1 Screen 1: minimum 8 x 8, current 2048 x 1280, maximum 16384 x 16384 DVI-D-0 connected primary 1024x1280+6+0 left (normal left inverted right x axis y axis) 376mm x 301mm panning 2048x1280+0+0 1280x1024 60.0*+ 75.0 1152x864 75.0 1024x768 75.0 70.1 60.0 800x600 75.0 72.2 60.3 640x480 75.0 72.8 59.9
If I swap connections on the DVI port to with the unplugged monitor, it remains at low power too… What is happening??
In summary, what seems to be happening is (tested),
- HDMI + 1x DVI - low power (either of DVI works)*
- 2x DVI - low power
- HDMI + 2x DVI - max power
- Note: 1x DVI means any of the 2 monitors that use DVI connection in either of the DVI connection ports on the video card (all 4 combinations)
I’ve also tested 3 X Screens instead of 2 where one had 2 monitors. 3 screens (one per monitor) also resulted in max power scenario.
It is still unclear to me when any combination of 2 out of 3 works, but 3 don’t. Since any combination works, then it must be true that any timing that must match for any 2 must also match for all 3.
PS. I may have been wrong to say that it worked in the past. At the time, one of the DVI monitors may have been broken (its power supply failed). Anyway, the problem remains with all 3 for unknown reasons. It cannot be related to timings unless you are saying that “timings only matter for more than 2 monitors but don’t matter for 2”.
PPS. Please keep in mind that manually forcing power mode to low with those PowerMizer config lines that were posted before, forced the video card into low power state. The problem then was that it would not leave that state. It functioned perfectly fine, it was just slow, and hence not very usable on demand for things like OpenCL or OpenGL.