I recently aquired a new high-end gaming rig, and its only now that I'm staring to have these vsync issues. When gaming with graphic settings on max, the the screen tears badly, especially in FPS games. If I turn on Vsync, which solves this, the game suddenly feels unplayably sluggish.
Current tv has 60hz refresh rate and is a 42" 1080P Toshiba LCD HDTV. this is plugged into two gtx570 cards in sli. is this issue to do with the cards or the TV, and if it's the TV, would I resolve the issue by getting a 100hz refresh rate LCD, or do I need a smaller monitor designed for PC use.
Screen tearing mainly occurs when the graphics cards are producing more frames per second than the monitor can ouput (in almost all cases, this is up to a maximum of 60 FPS).
In your case, this is very likely happening considering your dual 570's. It is strange you are getting sluggish issues with V-Sync as this should cap your frame per second output from your graphics cards to 60, the same as your monitor, and so should always be smooth and responsive. It is perhaps a driver error, try freshly reinstalling the latest drivers and see if that fixes it.
But you are right V-Sync is the main method to solve screen tearing.
Okay pal, cheers, will give it a go when I get home.
You might also want to try v-sync with triple buffering off and on to see if you can tell a difference. One known issue with triple buffering is that it can make input less responsive. If you'd normally have higher than your refresh rate in FPS with v-sync off, then you won't need triple buffering anyways.