Upgrade Thunderbolt Connection: From Version 1 to Version 2

#Dan

The point of changing the Thunderbolt version is to maximise the use of the egpu's graphic card capabilities.

With a Thunderbolt version 1 (10Gb/s) I would only be able to use about 50% of the Graphic Card capabilities.

Could I eventually upgrade my mother board: in order to have the Thunderbolt version 2 (20Gb/s) and keep all of my original components ?

I think you're over reaching on what you really need here.

While we would all love to have the fastest version of Thunderbolt in our system it's not the bottleneck when using external graphics when you have things daisy chained (the system to the box, then to an external display).

The bottleneck is only created when you need a dual stream back to your system to pump the output back to your internal display. Then I could see the need for Thunderbolt2. But remember this is using one channel (10 Gb/s) in each direction not bonding the two channels! So why would you use such a small display for such a powerful graphics engine setup? You wouldn't! It would be a waste.

Bottomline: Thunderbolt's original throughput is just fine. Here's a vid from Bison using a 2013 MacBook Pro (TB2) comparing it to a Mac Pro, you be the judge MacBook vs Mac Pro with dual BizonBOX external graphics cards (NVIDIA GTX) benchmark, review

As to altering things in your system with a logic board swap out not possible! Apple never offered a TB2 version of the original MacBook Pro. The current version Apple is still selling of this system (2012) still has a TB1 port. You would need to get to a Retina version of the system and then you would face the limits it imposes (Storage and possibility RAM).