So, i just bought the XFX Radeon HD5870. I hooked everything up, both PCIe 6pin connectors, and powered up.
When i plug my monitor in via DVI[Card] > DVI[Monitor], no signal.
When i plug my monitor in via DVI[Card] > Analog Adapter > VGA[Monitor], it works fine.
When i plug my HDTV in via DVI[Card] > HDMI[HDTV], no signal.
When i plug my HDTV in via HDMI[Card] > HDMI[HDTV], it works fine.
When i plug my HDTV in via DVI[Card] > Analog Adapter > VGA[HDTV], it works fine.
In summary, when i use the DVI cable or DVI port without an Analog adapter, nothing works. I get no signal to any displays. (This is not in Windows).
Monitor: Dual Link DVI-D
Cables: Both Dual Link DVI-D and Single Link DVI-D
HD5870: Dual Link DVI-I
If this helps.
I found out this isnt just a 5870 problem, ive searched the endless seas of the web and found many with this problem dating as far back as 2005.
Same problem with my old X600 DVI videocard.
Im beginning to think its software related.
Windows 7 64bit is the OS.
I guess i'll also add, that this no signal thing isnt IN Windows. I cant see system info such as BIOS or POST...as well as Windows.
Installed Windows XP SP3, still the same thing.
One thing is different:
I installed XP while i was using HDMI > HDMI on my TV (Since that works fine). When i plug in the additional DVI > DVI to my Monitor, the ATI Drivers, and the CCC (Catalyst Control Center) detects that there's another monitor plugged in, but i cant enable it. When i do, it just refreshes the screen, and its back to disabled. Same think for when i go into Desktop Properties>Settings and try to enable the monitor.
With Vista the ati 1950xtx card worked dvi - dvi
With Win 7 and ati 1950xtx, windows just ignored my previously working dvi connection and just worked with a vga adapter.
Upgraded gfx to a HD4770 but no change. But now not even bios/post shows without a VGA adapter.
I have 5760. I used dp -> dvi + hdmi -> dvi + dvi -> dvi. Everything worked fine.
Switched the dvi -> dvi to dvi -> vga for some time.
Switched back to the original configuration and boom.
The dvi -> dvi not working. Dvi -> vga still working.