I have a laptop with a gt 630m card. I was wondering if it would be possible to replace it with a gt 650m, if I brought it to some professional. I thought that this may be possible because the chips are of same size, but I'm not sure. And I'm not sure if other things matter.
My current laptop:
Lenovo Ideapad z 580
Intel Core i5-3210m
The BIOS would need to be able to identify the GT 650m. If it does not then the GT 650m would basically be unusable. Only Lenovo will be able to give you that information and they would probably be very reluctant to do so.
Additionally, the GT 650m puts out more heat than the GT 630m so the heatsink cannot deal with that extra heat, then your laptop will have overheating issues which can eventually kill your laptop.