Is monitor flicker a function of video card or monitor?

[Krzys Majewski <majewski@cs.ubc.ca>]

Can I take advantage of a new video card to reduce the flicker I 
see in X Windows, or is this strictly a function of the monitor? 
I copied the modelines from my old machine to my new machine and they 
work fine, but I'm wondering if I can do better. 
My new machine has an agp ATI Xpert98 (mach64) video card, as opposed to 
the (vlb?) Mach32 (Graphics ultra pro or something like this) card on my old
486. Same old "Enhanced VGA" monitor though. I have no docs on the monitor.
Any pointers to rtfm on the meaning of things like "hsync" and "vsync" and
"dot clock" also appreciated. 
Here's the relevant stuff from /etc/XF86Config:

Section "Monitor"
   Identifier      "Primary Monitor"
   VendorName      "Magnavox" # I typed this in
   ModelName       "CM2015D1" # I typed this in
   HorizSync       31.5 - 53
   VertRefresh     50-90
   Modeline "1024x768c" 65.0    1024 1036 1180 1304  768 771 777 802 -hsync -vsync
EndSection

Section "Device"
   Identifier      "Primary Card"
   VendorName      "Unknown"
   BoardName       "ATI Xpert 98"
   Chipset         "mach64"
   VideoRam        8192
EndSection

Section "Screen"
   Driver          "Accel"
   Device          "Primary Card"
   Monitor         "Primary Monitor"
   DefaultColorDepth 16
   SubSection "Display"
      Depth        16
      Modes        "1024x768c"
   EndSubSection
EndSection

-chris