eGPU solution for imac (octane / redshift)


Hi there,
After some time away from 3D I am getting back into the game and would like to use octane / redshift for my futur work.

I have read a couple of things here and there but can’t find a clear answer…

Is there an effective way to use eGPU with an imac ?

Thanks in advance for your response!

Here are my 2 imac specs:
iMac Core i7 3.4 27-Inch (Late 2012) / NVIDIA GeForce GTX 680MX 2048 Mo / 32Go RAM
iMac Core i7 3.5 27-Inch (Late 2013) / NVIDIA GeForce GTX 780M 4GB GDDR5 / 16Go RAM


check out for all about eGPU.



I have an iMac 5k 2014 and I’ve been successfully using the script which you can find on the website mentioned above… I’m running a sonnet breakaway with a 1080TI… It’s been working fine, just spend some time reading the info on the forums. The points worth mentioning are that the epgu needs to be switched on after boot up otherwise the system won’t start, and you can’t put the Mac into sleep mode, it’ll crash. I basically shutdown at the end of each day… Another point is that the script modifies system kexts and binaries (whatever that means), and I don’t think there’s any ‘uninstall’ process, other than reinstalling the Mac OS… There seems to be a new solution available called ‘automate egpu EFI’ or something, which apparently doesn’t modify your OS system files, but I haven’t yet read of anyone running it on an iMac, so I can’t vouch for it…

Something I find when reading the posts on the forum is that most people want to either hook up a second screen to their egpu or actually use it to run their main display… Like you, I just want my egpu for rendering, so have no need to make it run any display…

My personal home Mac is an iMac Pro… I’ve been meaning to set up my egpu on that, but for the time being I’m holding off until Mojave is released… I just want make sure the current egpu solutions will work OK with Mojave beforehand…

Worth mentioning too that I’ve been using mine for Redshift, which has been fantastic.


Banek - do you like Redshift more than Octane?


I started out using Octane, then I tried Redshift. I liked them both, but for some reason I just stuck with Redshift. I don’t really have much opinion about which is better and why, they’re both good…


Hi. I’m not sure how much of this info is still relevant after the release of Big Sur but I thought I’d ask anyway. I am very new to the whole eGPU thing and I want to buy one to use just like you - only for rendering, not to hook up a new screen. Are you still able to run yours? Thanks.


Things are easier now as Octane is available for OSX and Redshift will soon follow. They both support AMD graphics cards. I’d look at getting at least a 5700XT for reasonable performance. Hopefully OSX will soon support the new 6000 series of cards, which offer performance much more comparable with what’s available on the PC side. Getting hold of graphics cards at the moment though is a big problem.


It’s a good time to get In on OctaneX – it’s nearly finished (as in, the version 1.0 release). There is currently an issue with denoising in 11.1, but once that’s sorted, I think it’ll be really solid. I’m using it in C4D with a pair of 5700XTs (plus an RX580 when my free years sub turns up), and it’s great – really stable for working in the Live Viewer. I recently did a big animation using hi-res openVDB explosions, and it ran all night, no issue. Not sure about the eGPU thing – all my cards are internal – but once you see the difference in speed between Physical render and Octane, you’ll be hooked!


If you’re not on an MacPro you have to use an eGPU. I am waiting for the 6900xt, both physical availability and osx drivers of course. There is rumor of an M1 MacPro so it will be crucial to see if Apple still allows AMD cards to be used in the near future or that Apple own GPU’s will take over. If Apple updates the MacPro in 2021 with the latest AMD-cards, the driver issue will be solved. So a bit of patience or use an 5700XT for now. With Apple the distant future is always a bit hazy. They might change everything that you’re used to.
Octane-X rocks by the way!



IMO there’s no chance that a new MacPro will be released in 2021, it will come later in 2022. Basically Apple already confirm that from the start when Cook said it will take two years to complete the hardware transition, you can be sure the MacPro will be the latest system to get an M? SoC since the MP have the lowest commercial priority and the most complex hardware. No matter what the the M? will be, my guess is that next MacPro will still have PCIe slots and it should also be able to use AMD GPU, maybe even Intel GPU if they are happy to embrace Metal API.