Как в X Window задать при 800*600 частоту 75гц?

# 800x600 @ 100 Hz, 64.02 kHz hsync
Modeline "800x600" 69.65 800 864 928 1088 600 604 610 640 -HSync -VSync
# 800x600 @ 56 Hz, 35.15 kHz hsync
ModeLine "800x600" 36 800 824 896 1024 600 601 603 625
# 800x600 @ 60 Hz, 37.8 kHz hsync
Modeline "800x600" 40 800 840 968 1056 600 601 605 628 +hsync +vsync
# 800x600 @ 72 Hz, 48.0 kHz hsync
Modeline "800x600" 50 800 856 976 1040 600 637 643 666 +hsync +vsync
# 800x600 @ 85 Hz, 55.84 kHz hsync
Modeline "800x600" 60.75 800 864 928 1088 600 616 621 657 -HSync -VSync

А Xconfigurator не поможет ?