first of all: Yes, I have read the help page regarding tearing occuring with the eyefinity settings. As a matter of fact, I do not use eyefinity with my HD6990.
Instead, I just have my Samsung Syncmaster als well as my Philips TV (2012) connected by HDMI-> Displayport.
I have updated the drivers and tried every configuration possible in the catalyst control centre, including the one where I specify the resolution and frequency (60Hz) hoping for both screens working together having the same frequency but still there is tearing in every video and game as long as I have both screens plugged in. Deactivating one of them by Windows + P doesn't help.
Unplugging one of them is something I tried to avoid in the past as there has been trouble with my HD6990 shutting down the other screen aswell when one is plugged out (which required a reboot), so the option with Win+P is fine unless it comes to the horizontal and sometimes vertical stripes through the animated pictures. V-Sync does not correct this, either.
As and addition: I use both displays with the windows' setup making the TV an extended display.
I'm grateful for any advice related to this problem as I have found nothing on the net really helpful in this case. Thank you all in advance