Stock issues aside, the desktop GeForce RTX 4070 received praise when it launched almost two years ago and so it was only natural to expect something similar from the mobile RTX 4070 designed for laptops. Unfortunately, Nvidia would dash those dreams by cutting VRAM for the mobile version to just two-thirds of the desktop version (12 GB GDDR6X to 8 GB GDDR6X). The mobile RTX 4070 would ultimately perform more closely to the desktop RTX 4060 instead of the desktop RTX 4070.
Unfortunately, Nvidia will be repeating this same blunder yet again for the GeForce 50 series as the upcoming mobile RTX 5070 will only have 8 GB of RAM just like with the mobile RTX 4070. Instead of bumping the mobile RTX 5070 VRAM to match the 12 GB of the desktop version, a new SKU will be introduced called the mobile RTX 5070 Ti which will have the "full" 12 GB of VRAM. Even then, the desktop RTX 5070 Ti ships with 16 GB of VRAM as standard which further complicates the VRAM situation for the mobile Blackwell GPUs.
8 GB of VRAM is seen as a minimum or "budget" target when it comes to gaming even at 1080p to 1440p resolutions. The introduction of the mobile RTX 5070 Ti when there was never a mobile RTX 4070 Ti shows that Nvidia is pushing the mobile RTX 5070 down to the more budget-oriented category instead of pushing it up to match the upper midrange category of the desktop version. The next time you see the "recommended specifications" for an upcoming title, you can definitely expect the mobile version of the RTX 5070 to run a lot worse than its desktop counterpart.
Source(s)
Nvidia