We were quite skeptical regarding the existence of Ampere-based laptop GPUs, especially after seeing how high the TGPs of the high-end desktop models were, yet it looks like team green will indeed release RTX 3000 laptop GPUs apparently sooner rather than later, as a picture of the RTX 3070 mobility chip with version code GN20-E5-A1 already got leaked on the NGA Chinese forums.
Nvidia has been trying to keep TGPs for all Max-Q mobility GPU versions under 100 W, and this limitation clearly affects performance. Of course, Nvidia also provides non-Max-Q mobility versions, with the RTX 2080 Super model released earlier this year requiring north of 150 W. Now, the RTX 3070 desktop version is said to have a 220 W TGP, so we can expect a 120 W TGP for the mobility version, and this also allows for a sub-100 W TGP for the Max-Q version. There will probably be RTX 3060 mobility GPUs, as well, but we are not certain we may be seeing RTX 3080 versions any time soon, since these would require more than 200 W.
The leaked image of the RTX 3070 laptop GPU appears to depict a qualification sample of the same GA104 die that will be featured on the desktop-grade RTX 3060 Ti and RTX 3070. It has not yet been confirmed yet, but we believe the VRAM capacity for this GPU is 8 GB with 256-bit bus, as the picture shows eight distinct GDDR6 12 Gbps modules from SK Hynix. This would translate to a 384 GB/s total bandwidth which is already somewhat lower compared to the 448 GB/s on the desktop-grade RTX 3070.
Will the mobility RTX 3070 match the performance of the desktop counterpart? Probably not, considering the lower TGP which definitely means lower core clocks, plus there is the lower memory bandwidth, and we are not even sure that Nvidia will keep all the 5888 CUDA cores from the desktop SKU. Thus, the performance will certainly not match that of a desktop-grade RTX 2080 Ti, but we can expect a decent performance bump over the RTX 2080 Super mobility GPUs, and the release may be scheduled for early 2021.