What is the difference between these 2 graphics cards?

[Protectereli]

EVGA GeForce GTX 660 Ti 02G-P4-3660-KR Video Card - 2GB, GDDR5, PCI-Express 3.0(x16), 1x Dual-link DVI-I, 1x Dual-link DVI-D, 1x DisplayPort, 1x HDMI, DirectX 11, SLI Ready

EVGA GeForce GTX 660 02G-P4-2662-KR Video Card - 2GB GDDR5, PCI-Express 3.0(x16), 1x Dual-link DVI-I, 1x Dual-link DVI-D, 1x DisplayPort, 1x HDMI, DirectX 11, SLI Ready, Superclocked, Dual-Slot

Is one significantly better than the other? Heres the links to them

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=3712448&SRCCODE=WEBGOOPA&cm_mmc_o=mH4CjC7BBTkwCjCV1-CjCE&gclid=CNGIjL-Y-bMCFcaDQgod1mYAXg

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4501133&SRCCODE=WEBGOOPA&cm_mmc_o=mH4CjC7BBTkwCjCV1-CjCE&gclid=CM2r45qO-bMCFWrZQgodNzMAaQ

I am currently running a geforce gtx 240 nvidia card, how much of an improvement would i see by upgrading to one of these cards?

 

[Spaniard United]

The superclocked 660 has a higher core clock

The 660ti has more stream processors.

The 660ti is better, but not by a really significant amount.

You will definitely see much better results than your current GPU, provided your current CPU doesn't bottleneck them to oblivion.

 

[swilczak]

The 660 is about 6 times faster, and the 660ti is about 7 times faster than your current card. The 660 is a better value because of the recent price drop.

http://www.videocardbenchmark.net/video_lookup.php?gpu=GeForce+GT+240

http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+660+Ti

http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+660