There are a lot of fakes in China and India (most of Asia really) Where they market GPUs as one thing, but a close reading of the stats show they are not exactly what they claim. Some are just bold faced lies with the stats of one card pasted onto another. Or they will be cast off cripple GPUs that they can load the BIOS of faster cards onto, so like 1/4 or half of a working GTX770. (They love to show GPU-Z screenshots, to prove it is the real thing) Normally these would be sold as re-branded lesser products. You'll see OEMs in the US sell things like GTX745 which are quite similar, but at least they make a distinction.
Though Alienware was marketing some 3/4 cripple GTX760 as the full thing. 1.5GB of memory and a 192bit bus instead of the expected 256bit w/ 2GB.