Power Mac G5 Starts Up In DVI-A - Force to DVI-D?

I have a two month old Power Mac G5, 2.3 GHz dual core, 2.5 GB RAM, 250 GB hard drive. I paired it with a new Viewsonic VP2130b 21.3" LCD monitor. It is a great setup - it is hard to beat the Viewsonic for brightness, contrast ratio, response (8 ms vs. 16 ms. for the Apple displays) and so on.

BUT, it appears that both my Power Mac G5 and the Viewsonic support the little used DVI-A spec, which allows a DVI connector (of which there are two on the Power Mac) to drive analog RGB. Now of course both the Viewsonic and the Power Mac G5 support DVI-D too.

The problem? About 75% of the time when I turn my machine on, the Mac comes up and selects DVI-A instead of the desired DVI-D - rather like it is picking the lowest common denominator. This works just fine, but the display isn't nearly as crisp on DVI-A as it is on DVI-D. 99% of the time, just restarting the machine resolves the issue, with the Mac picking DVI-D the second time around. So, starting my machine almost always requires a start up and then a restart. This is annoying to say the least.

Does anyone know of any way to FORCE the Mac to start up in DVI-D? There don't seem to be any detailed controls availalable for the video driver, and so I am stuck with the very minimal Display preferences panel, which doesn't allow you to control such things. Is there some other software out there that would allow me to set this to always start on DVI-D?

I have checked the Viewsonic, there is no way to FORCE it to only look for DVI-D (as you would expect), and so I have to fix this on the Mac end.

Any and all thoughts much appreciated.

Hmmm, this seems sort of odd. What kind of DVI cable are you using and is IT DVI-A compliant. I just started using DVI-D between my G5 and Monitor and the cable I got said it only supported DVI-D.

I think baggss is right, you should get a DVI-D-only cable, to avoid the Mac to use DVI-A mode.

Excellent thought guys, thanks. I didn't realize that there was more than one kind of DVI cable. I am using the cable that came with the monitor - of course if *it* supports DVI-A, so does the cable. I will have to see if I can find a DVI-D-only cable and try again. Thanks!

You guys are brilliant. I did a little research on the web, and found out the differences between DVI-I and DVI-D cables (DVI-I supports both DVI-A and DVI-D). Then I unplugged the monitor cable Viewsonic had provided and examined it. Sure enough, it is DVI-I. I replaced it with an older DVI-D cable I had lying around and bingo! my Mac came right up in DVI-D. Brilliant! Thanks guys.

Glad it worked!