Accordingly, they are much weaker than their desktop counterparts
Chinese companies have reached the GeForce RTX 40 Laptop mobile video cards and started creating desktop cards from them.
In particular, in the vastness of Chinese online stores you can already find desktop adapters made from RTX 4080 Laptop and RTX 4090 Laptop. These cards are respectively called RTX 4080M and RTX 4090M.
Of course, since these are mobile GPUs, they are very far from their desktop counterparts. For example, the mobile RTX 4090 Laptop has 40% fewer CUDA cores, 8 GB less memory and a significantly lower TDP. As a result, in terms of performance it is approximately equivalent to the RTX 4070 Ti or the new RTX 4070 Super. The RTX 4080 Laptop, accordingly, is even less productive.
At the same time, of course, such converted adapters are much cheaper than full-fledged ones. For example, the Chinese are asking $420-560 for the RTX 4080M. The situation with the RTX 4090M is much worse: it is currently only available from one seller, and the price there is even higher than that of a full-fledged desktop RTX 4090 or the new RTX 4090D.