Is eGPU possible for an iMac 27-inch Late 2013?

[Yamcha]

Does anyone know if an eGPU would be compatible using a Thunderbolt 3 to Thunderbolt adapter? I haven't really found a solid answer online. The 755M isn't the best for gaming and I wouldn't mind upgrading if it would be possible through an eGPU solution.

 

[giffut]

Yes. You can try to replicate my setup: I use a Sonnet 550 egpu box, together with a Apple Thunderbolt 3/2 adapter and a Sapphire RX560 4GB graphicscard. Any AMD RX570/580 card is recommended, though, as they are natively supported by OSX. Still, with help from the community, other AMD cards run without hiccups.

My Macbook Pro 15 (2011) has 16GB RAM and a 512GB SSD and is running High Sierra 10.13.6 - this is important, because any version prior to 10.13.6 gave me insolvable problems. You should try disable FileVault and APFS file encryption if you got it enabled - in case you don´t succeed activating the eGPU. APFS file encryption generally is not recommendable at the moment for instabilities in general.

1. You need to run a script to activate support of the RX560 graphiccard itself and the thunderbolt 3 barrier Apple has erected: https://egpu.io/forums/mac-setup/script-enable-egpu-on-tb1-2-macs-on-macos-10-13-4/

2. The second script activates/uses Apples built-in support for enabling eGPU rendering for applications systemwide: https://egpu.io/forums/mac-setup/potentially-accelerate-all-applications-on-egpu-macos-10-13-4/

My setup runs stable and I especially get good support for rendering in iMovie and Final Cut Pro, but systemwide speedup, too. This makes my Macbook Pro competitive for a couple of more years. Your iMac would profit tremendously, too.