Videocardz has claimed that ZOTAC had accidentally posted a link for a new version of its GTX 1070-based Amp Extreme card - one with GDDR5X rather than the more usual GDDR5. However, this card has 8GB of this memory, as before, with the same number of CUDA cores. Then again, its TDP had increased.
Not long ago, we reported on indications of the impending release of a GDDR5X variant of the GTX 1060. This card could have improved on bottle-necking for the lower-end Pascal GPU, if not much else. Now, it appears that NVIDIA may repeat this trick with the GTX 1070. This possibiliy has arisen from a leak described in a new post by Videocardz.
The site asserts that GDDR5X was found among the specs of a new card, the "AMP Extreme Core GDDR5X" based on the 1070. Apparently, ZOTAC posted its details to its official website, then pulled them abruptly. Videocardz maintains that the relevant page is still available in Google Cache. It brings a RAM upgrade that was heretofore restricted to the GTXs 1080 and 1060 to the remaining Pascal card.
Most of the rest of the specs continue to match the former variants of the 1070, however. For example, its clock speed is still 1607MHz, with a boost to 1797MHz, and it has 1920 CUDA cores. On the other hand, its TDP has increased from 150W to 250W. This puts it rather closer to the GTX 1080, except in terms of CUDA cores obviously. Videocardz also claims to have a product image showing the new card's very slightly different packaging; however, it does not refer to GDDR5X anywhere on it. Therefore, we cannot say for sure that this new flavor of GTX 1070 will really be available soon.