Hardware: ATI GUPro PCI, mach32 graphics chip, 2 megs VRAM.
Software: XFree 3.1, mach32 server.
The problem is sort of strange. It occurs in both the modes I use,
one a 1280x1024 VESA mode, adjusted slightly for left-right centering,
and the other a home-rolled 1192x930. The pixel clocks are 135Mhz
and 126Mhz, respectively.
Both modes look perfect, except for a 1-2 pixel column on the side
of the screen -- right side for the 1280 mode at 135, and left
side for the 1192 mode at 126. What I get is, at first just a very
few pixels blinking on and off, the color of my X background, and then
more, and more, until I have a * sawtooth sort of pattern buzzing
along the side of the screen.
The funny thing is, when I start X it's not there -- not at all. It
begins when I pull up an xterm, is very minor at first, and then
builds. Once it's going it does not go away if I get rid of the xterm.
I'm wondering if something systematic is going on here, because the
problem is on different sides in different modes...leading me to
believe I might be able to shift it off the screen? I've fiddled,
but so far no dice.
I was able to previously run X at 135 Mhz with the same 1280x1024
mode on an ATI GUPro VLB, same monitor, without this problem
occuring. The monitor is a Nanao Flexscan 6500, BTW. It certainly
should be able to manage a 126Mhz pixel clock with no problems. I
am running right about dead on it's max horiz. scan rate, at 79.9khz,
with max being 80khz.
As I just bought this card, what I am wanting to know is if this
is probably a problem with this specific card -- i.e. should I send
it back for another? Or is this perhaps a problem with recent
mach32 cards? It's a VRAM card w/a max pixel clock of 135Mhz,
so should definitely handle a 126Mhz clock without any trouble.
Has anyone else experienced this? I'm thinking it's my card.
Any owners of recently-made PCI GUPros *not* having this problem at
126Mhz+ pixel clocks?
Thanks much in advance.
"Cavitas in dentibus facimus!"