When Nvidia releases their new Pascal-based notebook GPUs in the coming months, they won't be standard 'M' versions like we've seen in the past. Rather than cutting down the company's desktop GPUs to reach lower TDPs for gaming notebooks, Nvidia will simply release high-end desktop parts for laptops with only minor changes.
According to PC Gamer, citing unnamed sources, Nvidia will be bringing fully-fledged GeForce GTX 1070 and GTX 1080 GPUs to laptops. There won't be GTX 1070M or GTX 1080M variants; there will only be Nvidia's desktop-class Pascal GPUs repurposed for mobile form factors.
What Nvidia is doing here with Pascal is identical to what they did last generation when they released the GeForce GTX 980 for notebooks. The GM204 GPU variant was the same part used in desktop graphics cards, with the same CUDA core count and same boost clock speed, but at a lower TDP (closer to 145W than 165W).
If PC Gamer's sources are correct, Nvidia will be taking the philosophy that originated with the GTX 980 for notebooks and applying it to the entire Pascal notebook GPU line. Nvidia will reportedly be ditching their M variants entirely, and all future notebook GPUs will simply be repurposed desktop GPUs.
The lower TDPs of Nvidia's new graphics cards certainly help to achieve desktop/notebook GPU parity. The GTX 1080 is rated at just 180W, while the GTX 1070 is 150W, so if Nvidia can shave a few watts from these figures, they'll fit right in to the bounds of gaming notebooks.
By ditching M variants, Nvidia can streamline their design and manufacturing processes to reduce costs. For notebook gamers, this move will result in far more powerful gaming laptops with hardware comparable to high-end gaming desktops.
Nvidia is expected to reveal Pascal GPUs for notebooks in a few months' time. In the meantime, here's a taste what potentially a Pascal desktop-class GPU could do for notebooks soon enough -- taken from our recent review of the GeForce GTX 1070: