What is the difference between Palit GeForce GTX 960 Super JetStreamand Palit GeForce GTX 960 "Reference" 2048MB GDDR5?

[Toto_Samonte]

Do they have a big difference when it comes to performance?

 

[clutchc]

Since you didn't link to the exact cards you were comparing, I'm going to assume these are the two in question.
GTX 960 Super JetStream: http://www.palit.com/palit/vgapro.php?id=2440&lang=en&pn=NE5X960T1041-2061J&tab=sp
GTX 960 OC: http://www.palit.com/palit/vgapro.php?id=2442&lang=en&pn=NE5X960S1041-2061F&tab=sp

If so, you can see the main difference is the clock speeds and the cooler design. The Jetstream has a better cooler, but exhausts much of the heated air into the case. The "reference" design exhausts most/all the warm air out the back of the case... and may not cool as well as the other cooler.