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General Category => OSX and Graphics Cards => Topic started by: JimWright on June 14, 2014, 11:08:30 PM



Title: Help! Radeon 6870, Mac Pro, DVI filled with snow
Post by: JimWright on June 14, 2014, 11:08:30 PM
Hey folks, a while back I used the instructions at http://forum.netkas.org/index.php/topic,692.120.html to flash a XFX AMD Radeon HD 6870 for my Mac Pro 4,1.  Everything worked great with my old Cinema Display, I just picked up a larger display, a Dell U2713HM.

On my Mac Mini (via a switch box), the display looks great via DVI.  But on my Mac Pro, the display was visible but filled with snow, and would every few seconds go to all snow, before the screen would flash back to the mostly snow image.  This was running DVI through a KVM switch, so I went straight DVI from the Mac to the display, same issue.

My card has two DVI ports, so I tried the other port, after rebooting, same issue.  Tried two different dual link DVI cables, same issue.  Even knocking the resolution down to 1024x768 didn't help, it was definitely a signal problem and not a resolution issue.

My card also had an HDMI port, this works fine, but won't let me use the full resolution of the display.  There are two mini DisplayPorts on my card, but I haven't been able to dig up a spare adapter yet.

So, anyway, has anyone else run into a problem like this with their video cards?  Searching for 'Snow' just gets a lot of 'Snow Leopard' hits, so it's hard tracking this one down.  I'm not sure if there are any settings I can tweak somehow on this card that might help or not.