I currently have an ATI 5770 running dual display. However, recently I upgraded my 2nd display from a 19" 4:3 LCD monitor to a 21" 1080. Now I noticed this issue with my 2nd display flickering. I know this did happen on my old 19" but now that I use my 2nd display much more, it's becoming increasingly annoying.
From the research I've done, this seems to be a common ATI issue (I guess more so with the 4 series). I've tried upgrading to the latest drivers and have tried to play with the memory clock speeds. It seems if I overclock it even just a tiny bit, the problem becomes worse. At first it seemed to only occur when watching youtube videos but right clicking on the video, selecting options and disabling hardware acceleration fixed that. But when editing home videos this past weekend, I noticed every time I opened up a video the 2nd display flickered.
I am considering the idea of swapping out my ATI for an Nvidia card. Does this seem like a wise idea? Are people experiencing the same issue with some Nvidia cards too? If swapping to Nvidia is your recommended choice, what is the best performance vs. price card available? I am not a gamer, just want something with HD and dual display support.
Jaguar makes a good suggestion- it's always better to resolve the issue if possible.
I don't know what your warranty is or what brand of 5770 you have, but many cards have either 3 year or lifetime warranties. If you run into a dead end, I'd contact them and see what they can do to help you out. It's helpful if you have your proof of purchase with the purchase date, etc. Cheers!