MacOS Mojave was released on Monday and one of its lesser publicised features is easier external GPU support. Michael P Schmidt burnt the midnight oil testing out an eGPU with Final Cut Pro X. Prepare for a performance boost!

External GPU support doesn't really sound like a big deal, but it is probably one of the biggest processing changes to FCPX in a while. When Final Cut Pro was rewritten, Apple had the opportunity with X to move away from CPU calculating of tasks and move the pixel processing operations to the more efficient graphics card.

Thank the teenage gamers in their bedrooms who demanded instant renders of millions of polygons in their shoot-em-ups. This demand has since been overtaken by Bitcoin mining greed causing a shortage of the most powerful cards on the market.

Seven years on and our favourite NLE is still happily crunching pixels on the internal GPU. 

So when it was announced that High Sierra would support eGPUs, because FCPX followed the OS rules exactly (unlike Premiere that hacks its own way to the GPU), it became a prime candidate for harnessing this extra power. Render speeds were better, but users also reported problems, some tasks not happening on the GPU and other annoyances.

Michael P Schmidt had been testing eGPUs with FCPX and it seemed that with Mojave, although the external GPU was used for playback, the internal GPU was still being used for rendering. 

So why should the release of Mojave be any better? Well, with the release of Mojave, Apple published a short information page on using Final Cut Pro X and an eGPU.

Michael got to work straight away again and after spending the early hours of this morning testing and recording his new YouTube video, he came up with some interesting findings. And more importantly, how easy it is for FCPX to use an external eGPU. It is just a one checkbox.

So with Mojave, FCPX can now 'prefer' the eGPU for nearly all the tasks that require a GPU, so there is a performance gain to be had. FCPX will now go as fast as the card you have attached. Want to work faster? get a faster card! 

Could this be a hint at what the new 'modular' Mac Pro might contain? By modular, do Apple mean that they will have their own custom external GPU case? Who knows, but this update means that users can now get a significant performance update to their existing machine. (Possibly not our iMac Pro at this point) This will be especially good for users who need a portable solution such as a MacBook Pro, but need more grunt when they get to the office or back home.

So what do you need? First of all you need a Mac that supports Thunderbolt 3, have Mojave installed and of course an external GPU like the new Blackmagic model. Then find that checkbox!

Apple has a list of recommend GPUs and enclosures here. It looks like the Sonnet eGFX Breakaway Box 650W would be the one to go for.

A big thank you to Michael for doing the testing for the community.

Interesting times.