GTX 870M replacement for MSI GT780

Two weeks from now I will receive a junked-out Core i5 version of MSI's GT780. All that's left on the laptop was the unit itself with a broken GTX 580M card and the hard drive it came with. I want to restore the laptop to its full gaming glory and came looking for parts.

My primary priority is replacing the 580M with something substantial, as it was already kaput according to the first owner. I got a deal for a GTX 870M MXM unit for the MSI GT60. Will I encounter problems with this card? I was worrying that the card will be "whitelisted" from the board, rendering it incompatible. Should I flash the BIOS of the board before proceeding or the old one will work fine?

Umm, most likely the GPU will not be compatible. Unfortunately, I have no clue! Certainly would be interesting to see if it works though.

laptops and manufacturers, ugh.
Never know if shit will work or not, laptop customization is 0/10.

Unless it's an Alienware. Then it just supports whatever GPU from here back to 2009 so long as it isn't a Quadro or FirePro.

HP (owners of ayylmaoware) does wonky stuff like that too, whitelisting CPUs, not updating microcode and shit.

DELL owns Alienware. Have since 2009.

Yes, ayylmaoware.

Probably a good idea to try the 870M, and if it isn't compatible send it back. I know the 970M and 980M are compatible, so long as they have a Clevo or MSI vBIOS.

And I have no idea what the hell you are on about @thelonewanderer

Alien = ayylmao.