eGPU setup advice for DaVinci Resolve 15 / iMac late-2012 3,4GHz i7 - Mojave 14.1
Hello, I've recently registered and been looking for an eGPU setup for my work. Couldn't find similar scenarios in the build guides section but reading individual posts here and there it seems there's a workaround for my case (you can see my iMac model below, I'll double the RAM soon).
I mostly work with H264-H265 4K footage on DaVinci Resolve 15, using different openFXs, multiple nodes and some temporal NR. I somehow managed to get through crashes, reboots and hangs even with 4K DNG raw and 4K timelines, even though I export 90% in FullHD.
I need to boost my timeline playback speed more than export time as it's a priority for me to sync different camera's footage with audio tracks and node effects applied. I read there's no support in Mojave for Cuda so something like 1080ti is a no-go while a Vega64 or RX580 with a thunderbolt adapter (and the script) seems doable. The Blackmagic eGPU is thunderbolt 3 only. What enclosure has a good low noise level and goes well with these cards? I appreciate some help from whoever had to deal with a similar case and/or has an old Apple Thunderbolt 1 computer and is using Davinci Resolve (and if it's worth it regarding speed improvement). Also, How would an eGPU affect my usual 2-screens workflow? (the iMac and a thunderbolt Apple Display). Thank you so much, any advice is gold here.
iMac 27-inch, Late 2012 (3,4 GHz Intel Core i7 - 32GB 1600 MHz DDR3 - NVIDIA GeForce GTX 680MX 2048 MB)
Sonnet Razer Core X + Aorus Radeon RX580 8GB
I can't help you much about most of your questions, only this: I've read many people successfully connected TB3 enclosures to TB1 and TB2 ports using an apple TB3 to TB2 adapter.
BMD eGPU seems to be one of the quietest around. It's not the one I ordered though, since it was also much more expensive than most of the other options.
I have run Resolve on that model Mac in the past and it works. At the time it was Sierra with a water cooled 980Ti via TB1 >TB2 enclosure. Whilst the eGPU was rock solid and silent, I had issues with iMac thermals and crashes. I used Macs Fan Control software to run the fans at full speed to get around this when rendering RED. Which negated the quiet eGPU.
As Resolve relies heavily on GPU for compute 2Gig of VRAM is definitely hurting you. BUT thunderbolt 1 bus speeds are going to hurt as well. Thus I am not sure of the actual speed boost you are going to get with an eGPU. But what you will get is the ability to run and render any resolution footage with NR and OFX without GPU full render fails. I would recommend 8gig VRAM minimum.
If you are running Mojave you are stuck with AMD. Radeon VII offers a ton of VRAM but at TB1 you will not see a huge speed bump over a lesser card. But if you need to run 8K footage with NR then spend the cash. The card and eGPU will be useful long after the iMac has become a second screen.
Personally, I would run High Sierra, a NVidia 1080Ti (or if you can find one, a 980Ti), and use CUDA in resolve. Still a huge improvement over internal GPU.
Connection wise my set up is 2014 iMac > eGPU (TB2 Highpoint to PCIe) > BMD mini monitor. Second TB2 point is connected to the 2012 iMac which is now a second screen in Resolve. My guess is you will need something similar and will have to go for a eGPU with 2 TB ports.
Finally, if your goal is better playback performance and the Apple ecosystem, save the money you would spend on a eGPU and card, and invest in a 2019 iMac with Vega 48. The 2012 can become a second screen, and still be used for background rendering.