GeForce GTX 1080 gets full fat GP104 GPU with 2560 CUDA Cores. Literally the only difference between the mobile and desktop parts is the base clock, which is ~50 MHz lower on mobile part. Apart from that, we get full 8GB GDDR5X memory clocked at 10 GHz.
The GTX 1070 gets more CUDA cores than desktop variant 2048 CUDA Cores. The decision to increase the number of cores on laptop part was probably dictated by lower clocks, thus by increasing the number of CUDA cores, we still get similar performance.
Finally, the GTX 1060 has 1280 CUDA cores and 6GB GDDR5 memory. The mobile chip is simply lower clocked (1405/1670 MHz) than desktop variant.
More at - http://videocardz.com/63152/nvidia-launches-geforce-gtx-10-series-for-notebooks
Video Previews :
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Write ups :
Pcworld - Hands-on with Asus ROG G752 and GeForce GTX 1070 (or holy crap this thing is fast!)
Anandtech - NVIDIAs GeForce GTX 10-Series for Notebooks Unveiled, Launching Today
Techspot - Nvidia Pascal Goes Mobile: GeForce GTX 1080, 1070 & 1060 Preview
Tomshardware - Nvidia Launches Mobile Pascal: 1060, 1070 And 1080 Desktop-Class Graphics
Pcper - NVIDIA Pascal Mobile: GTX 1080, 1070 and 1060 Enter Gaming Notebooks