WCCF Tech notes there's a small shift in the video card landscape as NVIDIA's add-in board partners are phasing out the 2GB GDDR5 versions of the GeForce GTX 960 in favor of new models with 4GB GDDR5 memory. This move is intended to make the card more competitive versus the AMD Radeon R9 380.
Nvidia and its Add-in-Board partners have begun phasing out of 2GB variants of the GTX 960, leaving behind the existing 4GB variants as well as introducing some new ones. This probably comes in response to the fact that the GTX 960 under performs when compared to its price-rival: the AMD R9 380. The card was originally pitted against the AMD Radeon R9 280, which actually had a bus width of 384 bits and consequently, 3GB of vRAM. Since we are dealing with 1080p or lower resolutions, the bus width doesn’t really come into play (remember, Maxwell has some pretty amazing color compression technology) but with games like Shadow of Mordor demanding huge chunks of vram, 2GB is really too less for any modern day graphic card.