ASUS HD 6570 won't do dual-monitors with Dell Optiplex 745 Tower
Posted on 2012-04-10
Hi folks, I've been trying to get a group of computers up on dual monitors at my workplace. Actually, let me back up. I HAD these machines running with dual monitors already, but then had the genius idea of upgrading to Windows 7.
As it turned out, the video cards in the Dell machines are not supported in Windows 7. No biggie, found a card that I was able to find chatter online about as being functional in Windows 7 64-bit. That card is the ASUS HD 6570. Not a great card by any means, but perfectly good for office work.
Here's the issue I have. Only the VGA output works. These cards have a VGA, HDMI, and DVI output. I've read where people actually use all 3 outputs and drive 3 monitors with them. I'm using the same VGA to DVI adapters I used on the old cards, but there's simply no output on them. I don't have anything to test the HDMI port.
The BIOS on these Dells is confusing. There are only two options, 'Auto', or 'Card', but both options apparently disable the onboard video if a card is detected. In either case, the onboard video doesn't work as long as the card is installed, and that's not a big issue if not for the fact that the DVI outputs don't work on the card. And I've tried all 3 of them, so I don't think its a defective card or anything.
I downloaded the catalyst software and there's nothing in there that would seem to indicate the card needs to be 'turned on' in software. It should just be hot when the machine boots up.
Am I crazy? Missing something obvious here? I've updated the BIOS on all of these machines and they're completely up to date. I mention the OS but I'm not even sure why that would apply in this case. Is it possible that the BIOS is disabling the other outputs on the card? Why would it even do that?