RE: Just "installed" Radeon R7 250 graphics card on my Dell Optiplex 9020. Black screen when I plug the monitor into the card. Help!
I solved the problem. The DVI-to-VGA adapter that came with the card doesn't work. Once I used a DVI cord to connect to the card, it works fine and I no longer have the performance issues that I did.
Sorry I didn't post this earlier--when I figured it out my post was still in moderation so I couldn't update it.