According to Kitguru.net, couple of Nvidia AIB partners are introducing new versions of the Geforce GTX 960 graphics card with 4GB of memory, including Galax/KFA2, which included two new graphics cards – the GTX 960 4GB GAMER and a similar EXOC model, with a slightly different cooler design.
Since it will take time to phase out 2GB versions of the GTX 960, there are still plenty in stock, although they will not be replenished.
In case you missed it earlier, the GTX 960 is based on Nvidia's GM206 Maxwell GPU and packs 1024 CUDA cores (8 SMMs and 2GPCs), 64 TMUs, 32 ROPs and comes with either 2GB or 4GB of GDDR5 memory paired up with a 128-bit memory interface.
It is believed that most Nvidia AIB partners will introduce new 4GB versions of the Geforce GTX 960.