|The GTX650 does not SLI but it will be fine for now as riider says. If you insist on the POTENTIAL for SLI for the future, you need to go with the GTX650 Ti Boost (the regular Ti is not SLI either). The GTX650 and the GTX650 Ti should work with your power supply, the GTX650 Ti Boost probably will work with it for now (lists as 450W power supply required) if you want to eventually SLI it with another later when you upgrade BUT if you are going to wait more than 6 months, there will be newer cards out (the upper 700 series is out and the others will be out by then), then as mentioned, keep the price down so you can purchase the rest of the system sooner. If you are getting the rest of the system in say a month or two, try getting the Boost so if you find you need it, you can SLI it. If you are going to be much more than that, the GTX650 or GTX650 Ti will be a significant improvement over what you have and you will be thinking a new generation of everything by then so as already mentioned, save the money now. Even the GTX650 would be a decent starter for your new machine for a while and the upgrade later would be easier when you have the money.|
No, the SLI will not make much more difference on your current system so wait and get the system first.
--- I hope that clarifies my opinion better. I was not disagreeing, I was laying out another thought/option.
You have to be a little bit crazy to keep you from going insane.