I am looking to upgrade my XPS8300 video card to GTX560ti. Is this a good choice for photo editing and gaming (Diablo 3). And I also trying to make it as a Hackintosh. I am currently having a 6450 on my XPS8300.
What is your motherboard? That is the most important factor when building a hackintosh.
That GPU will (probably) be fine for a hackintosh (GeForce 500 series is supported by Mac OS), but you must make sure that your motherboard qualifies.
I'll need a bit more info than that to determine if it has USB 3.0, I'm afraid.
More specifically, motherboard manufacturer and model (chipset is not model)
EDIT: Intel H67 chipset supports hackintosh, supposedly. Therefore, you should be fine
EDIT 2: It only supports USB 2.0. Sorry
I was looking for a higher performance GPU and it seems like the 660ti and 670 have pretty good performance. I was planned to build another one in the coming year, which one do you think is good to go with?
a 4gb version of a GTX 660 ti would be useless. Just get the 2gb version. A GTX 660 ti is not powerful enough to utilise more than 2gb of RAM. Steer well clear of 4gb versions - they cost more for no improvement in performance.
Also ensure that you get a GDDR5 version, not a DDR3 version.