Originally Posted by jaaason
Run xvidtune. In the lower right, it says Vertical Sync. Of course, that requires you to see the screen.
The only other way I know how to check vrefresh is the X log: /var/log/Xorg.0.log or /var/log/XFree86.0.log. When the driver is validating which modes work for your hardware and config, it prints lines about the modes. Valid modes look like this:
*Default mode "1280x1024": 135.0 MHz, 80.0 kHz, 75.0 Hz
The star in front means that mode be tried first of all valid modes for that resolution (I think). The resolution that will be shown first is the first one listed in the Screen of xorg.conf. Anyway, the last value on that line is the vertical refresh.
For some reason, the log doesn't show lines like that in my current setup, nvidia-1.0-8756 with PCIe GeForce 6600.
diefool@veracity ~ $ xvidtune
Vendor: Monitor Vendor, Model: Monitor Model
Num hsync: 0, Num vsync: 0
Video are not settable on this chip
diefool@veracity ~ $ xvidtune -show
"1280x1024" 0.00 1280 0 0 0 1024 0 0 0
Not enough info