Maxon Cinema 4D Forum
iMac + eGPU + Cinema 4D
iMac + eGPU + Cinema 4D
by Chris Mathews on Dec 1, 2019 at 8:56:21 pm

Sorry if this has been answered before, but some research is bringing up conflicting answers.

I have been loving and using a Mac since 2004 and have no plans of switching to a PC, but I am curious if I could use a Mac with a eGPU and benefit from the speed and accuracy of a 3rd Party Renderer, like Redshift or Octane.

Is anyone successfully doing it?

Re: iMac + eGPU + Cinema 4D
by Jim Scott on Dec 1, 2019 at 11:30:52 pm

Sorry, but I think you're out of luck. Both Redshift and Octane require a CUDA-enabled Nvidia GPU.

Re: iMac + eGPU + Cinema 4D
by Chris Mathews on Dec 2, 2019 at 12:04:48 am

Thanks Jim. Could I just install an Nvidia GPU into a eGPU to accomplish this? Is the problem I can’t install CUDA on a Mac?

Re: iMac + eGPU + Cinema 4D
by Jim Scott on Dec 2, 2019 at 12:32:46 am

I'm not sure if this applies to your iMac, but in Octane's FAQ (#5 under Hardware and Software) they do talk about using a Thunderbolt controller with an external CUDA GPU (see screenshot below). CUDA drivers can certainly be installed on Macs (though there are no CUDA drivers available yet for Mojave), so your issue is going to be whether or not you can set up an external CUDA GPU. Contact support for whatever renderer(s) you're considering using and I'm sure they can give you the rundown.

Re: iMac + eGPU + Cinema 4D
by Chris Mathews on Dec 2, 2019 at 1:19:16 am


Re: iMac + eGPU + Cinema 4D
by Sam Treadway on Dec 2, 2019 at 2:14:47 am

Versions of Octane and Redshift are currently in development to support Apple Metal API.

Both have announced (through official and unofficial channels) that a release is eminent (perhaps by the end of the year or early in 2020) but this may be the start of beta. Since MAXON now owns Redshift and since many C4D artists are also on Mac, they are fully aware of the want and need. From what I've read recently, it appears that Apple is working very closely with both developers to implement the Metal counterparts as this will give Apple a better understanding of use in the wild (Metal) and will eventually pull in more sales from the high-end market. I don't see Apple directly supporting modern Nvidia products nor garnering support from Nvidia in the foreseeable future.

If you want to use an Nvidia eGPU you will have to work within macOS 10.13 and visit to learn about the hacks required and limitations for your specific hardware. Nvidia has also publicly announced that it will not continue developing CUDA for Mac. The Nvidia route (now) is like a nicely paved road that leads to a cliff where the alternative is to sit and wait for the even nicer road leading to an unknown paradise to be paved...however long it takes...

The question is: Do you want to put your money on something that can help right now but has no possible future path, or bide time and hope that these developments pan out. Redshift will be introducing a metal version for Mac users. Otoy, from what I remember, uses their own standardized code which goes through a middle translation layer where kernels are constructed based on the active API.

Other reasons to go with AMD now: If you use other tools such as DaVinci Resolve, Affinity photo or designer (adobe alternatives), then you can take avantage of the egpus with those and other tools right now.

Re: iMac + eGPU + Cinema 4D
by Chris Mathews on Dec 2, 2019 at 2:56:34 am

Thanks Sam, very helpful!