GeForce GTX 1080 Mobile GPU Specifications Leaked
 

So how does it differ from the desktop GPU? For starters, the mobile version will be using GDDR5 and have a memory clock of 8,008MHz. …the alleged mobile version of GeForce GTX 1080 features 2048 CUDA Cores, which is less compared to the 2560 CUDA Cores present in the desktop variant. The mobile version of this GPU is based on the new Pascal GP104 SKU and it's highly possible that it will feature a lower TDP compared to the desktop version. The desktop version of GeForce GTX 1080 is running at a default clock speed of 1607MHz, while the one that could be running in future laptops is running at a speed of 1442MHz.

http://www.hardocp.com/news/2016/06/...ations_leaked/