I got a powercolor x1600 pro with a top DVI and bottom VGA port, works fine but in VGA only mode. When I tried a different revision of a card I got DVI. The only difference is that the second card had dual dvi with one dvi port wired into an external TMDS chip (look for a chip near a port, usually a SIL xxxxx). The only DVI port that works is the one with an external transmitter, top one wired to the GPUs internal TMDS provides only analogue signal via VGA. This is an old story with apple, familiar to those who have flashed PC cards for apple use on PPC platform (refer to http://strangedogs.proboards40.com/index.c...read=1109820884 for example); apple cards use higher spec external TDMS while PC manufacturers save cost by using GPU's internal TMDS. Now, this is pure speculation on my part as I'm only basing this on 2 cards, but I thought maybe a quick poll might settle this.

Couple of points.

1) It's usually easy to see if a port is powered by external TMDS transmitter, find the TMDS chip then follow the traces.

2) a port that outputs VGA signal through a dongle is NOT a working DVI port.

3) if you are not sure if a chip is a TDMS chip, google it :-)


Thanks... if we are lucky this might be an easy way to sort good DVI cards from bad.

AND...

I'm very sorry if this comes under re-inventing the wheel category; I only had time for the briefest of forum searches ;-)


Oh... OOPS I messed up the poll wording a bit making it somewhat unclear, the top 3 options are for people with WORKING DVI, the bottom 3 are if you CANNOT get DVI only VGA.

This is interesting and should apply to all x1000 cards which can run under the x1000 kexts. Well only way to find out is to check the cards.
My x1800gto is using TDMS from the R520 chip, and DVI is not working.

I tried an X1600pro dual DVI (mouse tearing etc...) but DVI on external TMDS ONLY. I run out of X1*** cards I can borrow to try, BUT of the 3 I did, only external TMDS provided DVI.

If anyone has a X1*** (pref. 1600) that has DVI through the GPU TMDS; could you please post the make and model. This way I will know I'm barking up the wrong tree.