Performance between those two cards is rather similar. The GTX285 should be a bit faster then the GTX460 (stock anyways...) and the GTX650TI is faster then that as well. I wouldn't have bought the GTX650TI, its more of a sidegrade.
It shouldn't do any worse then what you had before. Seeing as you already updated the drivers, I'd try removing all drivers, run the driver sweeper program, and install the newest one. Also make sure you are comparing the cards with the same settings.
That's definitely odd, the 650 ti should be about 30% better than the 285. I honestly don't know what could be wrong unless you have a defective card.
650Ti and GTX285, both of card in the same tier, depend on what game are you playing 650Ti just a hair faster than GTX285..
you can't say that hair as a 30%..
yes, this is side grade, not an upgrade..
But why it perform worse..?
Quick and dirty analysis..
285 still in dx10, and 650Ti is in dx11..
while your playing games, some of games automatically set to dx11 while you set highest setting available, and 650Ti -as a low mid class gpu - is not strong enough to server playable fps to your monitor
but when you play your game in gtx285 -very high end, king of the hill in 2xxx series - , it just running at dx10 mode, lighter load to gpu processing, as a result give higher fps..