Quadro 420 limited to 1280x1024 for each of the 4 displays

[James Bowery]

Nvidia's specifications for the Quadro 420 state:

"Drive up to four 30’ displays at 2560x1600 resolutions"

After a couple of days trying variations, I discovered the only way I could get 4 displays working properly was to set them all to 1280x1024. If any of the 4 were set to a higher resolution via the System Settings -> Displays -> Resolution, it would do various buggy things.

Here's my configuration:

# apt list --installed|egrep -i "nvidia|nouveau"

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

libdrm-nouveau2/zesty,now 2.4.76-1 amd64 [installed]
nvidia-340/zesty,zesty,now 340.102-0ubuntu3 amd64 [installed]
nvidia-opencl-icd-340/zesty,zesty,now 340.102-0ubuntu3 amd64 [installed,automatic]
nvidia-prime/zesty,now 0.8.4 amd64 [installed,automatic]
nvidia-settings/zesty,now 381.22-0ubuntu0~gpu17.04.1 amd64 [installed]

# lspci -k | grep -iEA3 '3D|VGA'
03:00.0 VGA compatible controller: NVIDIA Corporation G98 [Quadro NVS 420] (rev a1)
 Subsystem: NVIDIA Corporation G98 [Quadro NVS 420]
 Kernel driver in use: nouveau
 Kernel modules: nvidiafb, nouveau, nvidia_340
04:00.0 3D controller: NVIDIA Corporation G98 [Quadro NVS 420] (rev a1)
 Subsystem: NVIDIA Corporation G98 [Quadro NVS 420]
 Kernel driver in use: nouveau
 Kernel modules: nvidiafb, nouveau, nvidia_340

# uname -a
Linux jabowery-H61M-S2-B3 4.10.0-21-lowlatency #23-Ubuntu SMP PREEMPT Fri Apr 28 18:21:43 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux