PowerMac G5 (PCIx/AGP) - getting full 2560x1600 resolution through Dual-Link DVI - ATI Radeon 9650
My ATI Retail Radeon 9600 Mac&PC 256MB AGP card broke, so I dug through my other cards over the ages and couldn't find one that would support native (2560x1600) resolution of my 30" display. Needless to say this is a legacy system I'm trying to keep going, and I really don't want any changes to it at this point. My apps and docs are set up to use the full 30" screen resolution.
A good resource on Apple G5 Video cards can be found at :
The ATI Retail cards (256MB above) provided 2560x1600 support and had extra options in their driver control software, but Apple had some limitations placed in the ROMs of the otherwise exact same cards.
I fought with this, and found a description of the Apple OEM Radeon 9650 that said that it has "two DVI ports, one Dual Link and one Single Link" I had previously interpreted that if you hook up a 30" monitor to one of them, the other would only display in Single Link mode, but then it dawned on me that these were hard wired DVI ports with different specs. Sure enough, connecting to the upper port on the Apple Radeon 9650 256MB Pro card gave me full resolution. It doesn't get any extra bells and whistles of the Radeon Control Panel, but it gave me what I needed, which was full 30" resolution for simple 2D windowing.
Thought I'd share this with others trying to keep older G5 systems up and running at their full capabilities. The video cards are now the likeliest component to fail (and most difficult to replace) because you can always find RAM and HDDs (or SSDs), but the thermal paste that cools the video card GPU gets old, dry, and cracked, and eventually the GPU overheats and gets damaged. You might consider checking and replacing the paste under the heat sink on a card that still runs.