$ sudo xresprobe sis
id:
res: 1280x1024 1024x768 832x624 800x600 720x400 640x480
freq:
disptype: crt

$ sudo xresprobe nv
id:
res: 1280x1024 1024x768 832x624 800x600 720x400 640x480
freq:
disptype: crt