You will be happy if you find a newer gen standard MXM3b card. The last standard sized cards were 82x105mm was the GTX 1080 8GB model and the Radeon Rx480. However after the GTX 1060 MXM3b variants they do not support LVDS output any more only eDP displays, and beyond the 1070 they also need power. The RTX series still exist, but they are physically on a larger larger pcb, 100x 124mm boards, and they will need a dedicated power input for the max 150w. For some reason, MXM is dead as a dodo these days. Technically nothing stopping them to use the slots, however MXM3b laptops were way too easy to upgrade and they don't want you to upgrade your old unit. I have a GTX 680M 4GB model in my old M17x-R2 instead of the dual Mobility Radeon 5870's in CrossfireX setup.