In some email I received from Jared D. McNeill, sie wrote:
> Is there anyway to change the resolution or refresh rate with a cg3 in a
> SPARCstation 10? It looks like the default is 1152x900@76Hz, and a quick
> Google search shows that my monitor (ViewSonic G653) will do
> 1152x860@75Hz, but no mention of the previous mode.
> 
> Anyway to drop the resolution to 1024x768, or drop the refresh rate a bit?

You should find all the answers to your questions at:

http://www.sunhelp.org/faq/FrameBuffer.html

Try and get yourself a better frame buffer too, the CG3 is OLD and SLOW.
A TGX or TGX+ is much better :)

Darren