steev@solene:~$ grep mode /var/log/Xorg.0.log
(--) I810(0): Maximum space available for video modes: 8000 kByte
(II) I810(0): Not using mode "1280x960" (no mode of this name)
(II) I810(0): Not using mode "1024x768" (no mode of this name)
(II) I810(0): Not using mode "800x600" (no mode of this name)
(II) I810(0): Not using mode "720x400" (no mode of this name)
(II) I810(0): Not using built-in mode "1600x1200" (width too large for virtual size)
(II) I810(0): Not using built-in mode "1280x1024" (width too large for virtual size)
(II) I810(0): Not using built-in mode "1024x768_60.00" (width too large for virtual size)
(II) I810(0): Not using built-in mode "800x600_60.00" (width too large for virtual size)
(II) I810(0): Increasing the scanline pitch to allow tiling mode (640 -> 1024).
(**) I810(0): *Built-in mode "640x480"
(II) I810(0): Attempting to use 85.01Hz refresh for mode "640x480" (841)