GeForce GTX 960 video cards with 4GB GDDR5 memory are now available. The manufacturers are GIGABYTE (two products) and Palit (one product).
The products are the GV-N960G1 GAMING-4GD and GV-N960WF2OC-4GD from GIGABYTE and the GeForce GTX 960 JetStream (NE5X960010G1-2062J) from Palit. All feature a doubling of the installed memory from the reference design's 2GB to 4GB.
All three products from the two companies are positioned as increased memory versions of the existing 2GB GV-N960G1 GAMING-2GD, GV-N960WF2OC-2GD, and GeForce GTX 960 JetStream models, and have the same operating clock, monitor output configuration, and cooler.
However, only the two GIGABYTE products have changed the auxiliary power connector from a single 6-pin to a 6-pin + 8-pin configuration, and the GIGABYTE GV-N960WF2OC-4GD has a new back plate (the 2GB version did not have a back plate when it was released).
Prices are as follows
GV-N960G1 GAMING-4GD
35,900 yen (excluding tax): Tsukumo eX.
38,680 yen (including tax): BUY MORE Akihabara flagship store
38,772 yen (w/tax): PC Shop Arc
38,859 yen (including tax): Dospara Parts Building
GV-N960WF2OC-4GD
33,900 yen (w/o tax): Tsukumo eX.
36,480 yen (tax included): BUY MORE Akihabara Main Store
36,612 yen (w/tax): PC Shop Arc
36,699 yen (including tax): Dospara Parts Building
GeForce GTX 960 JetStream (NE5X960010G1-2062J)
32,980 yen (excluding tax): DOSPARRA Parts Department Store