Can't set refresh rate on G400MAX

[ChrisDent]

I have set my refresh rate at 2048x1536 at 8/16/24 bit to 73Hz, but for some reason the 2048x1536x32 refuses to let me set it to anything above 67Hz (the speakers give the error chime if I try to use the up-arrow to increment the refresh) -- its as if the software thinks that either the graphics card or monitor won't like a higher setting.

Does anyone know what could be causing this?

[arbymo]

i don't have a G400 myself, but it looks like a memory bandwidth limit.

Wait for a confirmation from other G400 owners though.

[Maggi]

Re: Can't set refresh rate on G400MAX

Originally posted by ChrisDent
I have set my refresh rate at 2048x1536 at 8/16/24 bit to 73Hz, but for some reason the 2048x1536x32 refuses to let me set it to anything above 67Hz (the speakers give the error chime if I try to use the up-arrow to increment the refresh) -- its as if the software thinks that either the graphics card or monitor won't like a higher setting.

Does anyone know what could be causing this?

Are you sure you're using a MAX ???

The limit you describe above is exactly the limit of a 300MHz RAMDAC ...

What monitor profile are you using ?
(and what monitor on that occasion ?)

[ChrisDent]

I am positive that it is a max (that's what I paid for - can't find the manual at the moment, but dual-head, 32MB and a fan (from my semi-reliable memory the regular G400 was passively cooled -right?).

The monitor is a Philips "Brilliance 201P" (21", rated to 243MHz - well below what the vanila G400 can pump out)

I have ticked the box labeled "Use customizations to Windows monitor settings (Customized by users)". I guess that means my monitor profile is the one provided by MS. Of course it has now been tweaked.

I was not aware that the colour depth had any effect on the bandwidth of the RAMDAC

[ChrisDent]

arbymo was right, it was a memory bandwidth issue

I turned on the advanced settings and discovered that if kept all the parameters the same, but varied the colour depth the value of the pixel clock changed (it got smaller the larger the bpp)