Highlander wrote:
I wonder if these cards could be retrofitted to the g75vx

Even if you could (and no, you can't; the G75 internals are completely different than the G750's) the cooling would be inadequate.

The only cards you can "technically" swap in and out of the G75 are 660m, 670m and 670mx. And you can only do this with the ASUS variants that the G75 used due to it's proprietary shape and cooling solution.

Not to mention that even though you can technically do swaps with the aforementioned cards, you still have to mod the G75 BIOS to swap out each cards respective VBIOS since the G75 has the VBIOS embedded inside it's own BIOS.

In other words; if you have a G75VX with a 670mx card, then you're running the most powerful card available to you for your notebook. Your only options for better performance are CPU upgrades (use only those with same watt rating), RAM upgrades (use only those with same watt rating), SSD upgrades; or unlocking the 670mx VBIOS and applying at OC higher than stock boost. You can also volt-mod the VBIOS to attain a higher OC, but this is a tricky balance of volts, heat clock and stability.