I am running Ubuntu 12.10 on HP Pavilion Slimline with Nvidia GT220 video card and Nvidia driver 310.14. I have Samsung LCD connected through HDMI, native resolution of this TV is 1366x768, but the only options I am getting in settings are 1920x1080, 1280x720, 720x480 and 640x480. I'd like to run in native resolution, so how can add it to the list of available options? I tried to use xrandr, but not sure what are correct values to enter or whether it's the right way to go.
Edit
After running cvt 1366 768 60 I got the following:
# 1368x768 59.88 Hz (CVT) hsync: 47.79 kHz; pclk: 85.25 MHz
Modeline "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync
Then running xrandr I have
Screen 0: minimum 8 x 8, current 1280 x 720, maximum 8192 x 8192
DVI-I-0 disconnected (normal left inverted right x axis y axis)
VGA-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1280x720+0+0 (normal left inverted right x axis y axis) 160mm x 90mm
1280x720 60.0*+ 59.9
1920x1080 30.0 30.0
720x480 59.9
640x480 59.9
1368x768_60.00 (0x2aa) 85.2MHz
h: width 1368 start 1440 end 1576 total 1784 skew 0 clock 47.8KHz
v: height 768 start 771 end 781 total 798 clock 59.9Hz
However, when running xrandr --addmode HDMI-0 1368x768_60.00, I get:
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: 29
Current serial number in output stream: 30