here is what i know, its a rough translate but you guys can get the drift:
"3DMark 11 test, GTX 560 Ti 448 Cores can get X1800 multisection, GTX 570 points can be close to the X2000, a difference of less than 8%.
3DMark Vantage P level, GTX 560 Ti 448 Cores can run out of P25700 multisection, GTX 570, there are almost P27500, a difference of 6% points.
N card used Unigine Hevean project, 1080p resolution and normal surface subdivision setting, GTX 560 Ti 448 Cores results about 45FPS, GTX 570 is 48FPS or so, and if open to the highest surface subdivision, the two scores were to 35FPS, 38FPS.
"Lost Planet 2" 1080p resolution, high quality, A test project, GTX 560 Ti 448 Cores rate of about 50FPS, GTX 570 faster than in the 6FPS, more than 10%.
In general, GTX 560 Ti 448 Cores compared to the "full version" of the GTX 570 games behind the average speed of about 7%, still acceptable. "
Main important thing. should be 7% of a 570. varies game to game.