I’m using drivers 346.47 on my GTX 750 with a 4k dell P2715Q on DisplayPort and two 1080p monitors over HDMI, with the dell as my primary monitor. After the monitors would go to sleep with DPMS (turning them off would produce the same behavior), most of the time when they woke up X would be reconfigured with the DP and one HDMI monitor disabled (like 9 out of 10 times). Setting ConnectedMonitor to “DFP-0,DFP-1,DFP-3” and using CustomEDID (specifying EDID files saved with nvidia-config) in my xorg.conf fixed that, but now, despite having only a single metamode:
Option “metamodes” “HDMI-0: 1920x1080 +5760+0, DVI-I-1: 1920x1080 +0+0, DP-1: 3840x2160 +1920+0”
Option “IncludeImplicitMetaModes” “off”
After restarting X, or after DPMS puts the monitors to sleep, the 4k monitor still comes up scaling to 2560x1440, rather than at its full resolution. (The 1080p monitors come up at 1080p.)
Is there any way to really and truly limit X to just 3840x2160 on my 4k monitor, and no other resolutions, so I can finally put my monitors to sleep without having to reconfigure the 4k monitor every time it wakes up (nvidia-settings can restore it to native resolution on the fly, i.e. by choosing that, pressing “Apply”, and then saying yes to the dialog which asked if I want to keep it)?