The NVIDIA GeForce RTX 2080 for laptops is the fastest mobile graphics card for notebooks in early 2019. It is based on the desktop RTX 2080 but with reduced core speeds (-7% Boost, -9% Base). The memory appears to be similar clocked and sized. Therefore, the RTX2080 offers 2,944 shaders and 8 GB GDDR6 memory connected by a 256 bit interface (14 GHz, 448 GB/s).
NVIDIA manufacturers the TU104 chip on a 12 nm FinFET process and includes features like Deep Learning Super Sampling (DLSS) and Real-Time Ray Tracing (RTRT), which should combine to create more realistic lighting effects than older GPUs based on the company's Pascal architecture (if the games supports it). The RTX 2080 is also DisplayPort 1.4 ready, while there is also support for HDMI 2.0b, HDR, Simultaneous Multi-Projection (SMP) and H.265 video en/decoding (PlayReady 3.0).
The mobile RTX 2080 should perform a bit slower than the desktop RTX 2080 and therefore definitely faster than the old GTX 1080 for laptops. Therefore, it should be able to run all demanding games in 4k with maximum details. Raytracing features however may reduce framerates a lot.
The power consumption of the card was reduced from 215 Watt for the desktop RTX 2080 to 150 Watt. However, it is still only suited for thick and heavy gaming laptops. For thinner and lighter designs, the Max-Q variant of the RTX 2080 is intended that can be configured at 80 or 90 Watt (at much lower clock speeds).