I am trying to maximize my resolution where I have Resolution: 800x600 (4:3) and Refresh rate: 61Hz I tried the following, but it did not work: $ xvinfo X-Video Extension version 2.2 screen #0 no adaptors present $ cvt 1920 1080 # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync $ xrandr --newmode clever_name 173.00 1920 2048 2248 2576 1080 1083 1088 1120 $ xrandr -q Screen 0: minimum 640 x 480, current 800 x 600, maximum 800 x 600 default connected 800x600+0+0 0mm x 0mm 800x600 61.0* 640x480 60.0 clever_name (0x11d) 173.0MHz h: width 1920 start 2048 end 2248 total 2576 skew 0 clock 67.2KHz v: height 1080 start 1083 end 1088 total 1120 clock 60.0Hz $ xrandr --addmode default clever_name $ xrandr --output default --mode clever_name xrandr: Configure crtc 0 failed