I have fresh-installed Ubuntu 14.04 over the weekend on my Dell E6520. The nouveau driver didn't allow me to use maximum resolution for my laptop display. Switching to the nvidia (proprietary, tested) driver solved that issue.However, my external display (Dell P2412H) shows up as 'Unknown display' in 'Displays' and allows maximum resolution of 1360 x 768 (should be 1920 x 1080). Switching back to nouveau doesn't help with either display.
$ xrandrScreen 0: minimum 8 x 8, current 3280 x 1080, maximum 16384 x 16384VGA-0 connected 1360x768+1920+0 (normal left inverted right x axis y axis) 0mm x 0mm1024x768 60.0 +1360x768 60.0* 59.8 1152x864 60.0 800x600 72.2 60.3 56.2 680x384 60.0 59.8 640x480 59.9 512x384 60.0 400x300 72.2 320x240 60.1 LVDS-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 194mm1920x1080 59.9*+ 39.9 DP-0 disconnected (normal left inverted right x axis y axis)DP-1 disconnected (normal left inverted right x axis y axis)HDMI-0 disconnected (normal left inverted right x axis y axis)DP-2 disconnected (normal left inverted right x axis y axis)DP-3 disconnected (normal left inverted right x axis y axis)1920x1080_60.00 (0x2d0) 172.8MHz h: width 1920 start 2040 end 2248 total 2576 skew 0 clock 67.1KHz v: height 1080 start 1081 end 1084 total 1118 clock 60.0HzI tried to force the new resolution via randr, but without much luck:
gtf 1920 1080 60# 1920x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 172.80 MHzModeline "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync:~$ xrandr --newmode "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync:~$ xrandr --addmode VGA-0 "1920x1080_60.00"X Error of failed request: BadMatch (invalid parameter attributes)Major opcode of failed request: 140 (RANDR)Minor opcode of failed request: 18 (RRAddOutputMode)Serial number of failed request: 37Current serial number in output stream: 38Just in this is of importance, here's some info from glx:
:~$ glxinfo | grep renderdirect rendering: YesOpenGL renderer string: NVS 4200M/PCIe/SSE2GL_NVX_conditional_render, GL_NVX_gpu_memory_info, GL_NV_conditional_render, GL_NV_copy_depth_to_color, GL_NV_copy_image, GL_NV_parameter_buffer_object2, GL_NV_path_rendering, GL_NVX_conditional_render, GL_NVX_gpu_memory_info, GL_NV_conditional_render, GL_NV_copy_depth_to_color, GL_NV_copy_image, GL_NV_parameter_buffer_object2, GL_NV_path_rendering, EDIT: Just to get that out of the way: I have reconnected the cable multiple times. VGA is the only option right now - the laptop has VGA and HDMI outputs, the display has VGA and DVI inputs.