Currently at NEWEGG, a GTX 460 (768Mb) sells for ~ $140 after rebates.
A GTX 570 (1.28GB) sells for about $270
I recently purchased the GTX 460, but I was seeing some artifacts the other night that were occurring on my desktop and prevented me from loading any games.
I thought about stepping up to the 570 because I am still within 90 days... or I could get a 2nd 460...
I haven't been able to re-produce the artifacts I was getting the other night, but I was not overclocking and checked the temperature on the card which was around 35 C
Thanks for the suggestion, but if exchange the card with the step up program the 560 might not be an option.
I wonder if the 560 would outperform the 570, I am doubting it will, but the price break might be an option if I choose to go SLI.
I don't mind spending the $150 to upgrade from 470 to 570... I was more concerned with how a 460 in SLI would compare to a single 570, but as Bystander wrote, performance will vary depending on the game, and it seems wiser to go with the 570.
A single 570 now would give you the option to SLi later perhaps and unlike bystander I have found that most of the games that I have played over the last six years or so have utilized SLi.
Most games I have played also support SLI, but not all. Some just performed like a single card, some have added glitches. When picking a card to start with, a single card is usually best, unless you are already at the high end and want more power.
And like you said, you can SLI later down the road.