eGPUs on Macs: Impressive Performance Gain but Plenty of Limitations

macOS High Sierra title headline

Last month, Apple released macOS 10.13.4 High Sierra with support for eGPUs. With most Macs coming with low-end or mid-range GPUs, support for external GPUs will allow developers and gamers to attach an eGPU to their compatible Mac for improved performance when required.

But how good is the overall experience of using an eGPU on a Mac? Is the investment worth the performance improvement? The folks over at Ars Technica took an AMD RX580 inside an external GPU enclosure for a spin on their 2016 MacBook Pro to find out.

One of the most impressive aspects of native eGPU support on macOS is that you can simply plug in the eGPU before starting the Mac, and that’s about it. There’s no other set up required from the software part. The GPU will be automatically detected and all the work will be offloaded to it. You can even switch between the integrated and eGPU without having to reboot your Mac. Even better, if the power supply and your GPU enclosure are powerful enough, it will not only power the GPU but also charge your Mac — all from a single cable!

There’s a catch in how Apple has implemented eGPU support in macOS though. An eGPU will only power an external display and not the built-in display of your Mac. So, even if you plug in an eGPU in your compatible Mac, it will not take advantage of it until and unless you plug in an external display to it.

What about the performance improvement though? Using a 2016 15-inch MacBook Pro with TouchBar featuring a Core i7 6820HQ processor and a AMD RX460 internal GPU. This was paired with an AMD RX580 eGPU. The performance improvement varied from test to test but they were still anywhere between 20-75 percent. For example, Cinebench’s OpenGL test saw a 50 percent boost in scores while benchmarks that made use of Apple’s Metal API saw a 2x increase in performance. There’s a catch here as well though. Developers will have to update their apps to take advantage of the external GPU. Hitman, for example, kept crashing with the eGPU enabled. Similarly, and perhaps most disappointingly, Apple’s own Final Cut Pro X does not make use of the eGPU for faster render times. But on the other hand, Blender makes use of the eGPU to offer faster rendering performance.

Overall, as the article states, eGPU on a compatible Mac is definitely worth it provided the software you want to use is capable of taking advantage of it. The performance improvements are significant which make up for the investment that you have to do in the GPU and the external enclosure.

Have you tried using an eGPU on your Mac yet? If yes, how was your experience?

[Via Ars Technica]

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