However, that may not be the case with the GPUs:
According to our information, it is possible to change the graphics card in this machine. In fact, the GPU is placed on a daughter card, it is possible to remove and thus replace. As you might expect, Apple uses a proprietary connector (as is the case for SSD array present on the rest of the range). But nothing prevents, on paper, a manufacturer decides to offer compatible models on the market. It is even possible that Apple, medium, offers homes in collaboration with AMD solutions.
Two workstation-class AMD FirePro GPUs with up to 12GB of video memory provide up to seven teraflops of compute power and up to eight times the graphics performance of the previous generation Mac Pro. It will be available in December starting at $2,999. More details on the device can be found here.
Read More [via Sav]