Radeon VII on an iMac Pro: not speeding up Resolve... at all
Tested in HD, UHD, different formats. Both in OpenCL and Metal (much faster). Tried hooking up a display or keeping the eGPU only for compute: no difference. Using 50cm TB3 cable.
Right now having an eGPU feels useless.
Do you see activity monitor using it?
Maybe Catalina can help, I've seen many times issue like that fixed by OS update.
Thanks for your feedback -not a big fan of Catalina but if it may help I'll surely have to upgrade.
Can't run it on both GPUs simultaneously, but how do you see this geekbench 5 numbers?
-eGPU Radeon VII 60885 Metal Score
-internal Vega56 69086 Metal Score
-eGPU Radeon VII 56728 OpenCL Score
-internal Vega56 58329 OpenCL Score
Resolve is known for making very good use of multiple GPUs, my previous rig had 2x1080Ti and it nealy doubled the speed of a single 1080Ti... But when using both it's slower than the internal Vega 56 only...
I see regular iMacs delivering 90k+ when mine is at 60k, so the figure is indeed bad:
What can be going wrong?
I tried the same Sonnet 650w box on an iMac, 6-core @3,7Ghz, internal 580. With Catalina!
The Geekbench result is even worst: 55.000 in Metal for the Radeon VII.
There are no drivers or firmware for the box, i didn't install radeon drivers either. I tried different thunderbolt 3 cables... ANy idea how to. spot the issue? Thanks!
You’re using the wrong benchmark. GB has been useless on Mac OS for some time.
All Mac users should run the Basemark GPU for Metal benchmark.
And while an eGPU speeds up some tasks in DaVinci Resolve - that doesn’t mean it speeds up all of them on every Mac model. (The same applies to Final Cut Pro).
Barefeats testing shows this pretty clearly.
And here’s another example where adding an eGPU does help - when noise reduction processing is involved. (Ignore the Mac Pro comparison for the moment).
@mini-i5, Thanks for getting back and providing useful info.
Barefeats has been a reference and actually one of the reasons why I purchased the Radeon VII.
I asked Rob (aka Mad Scientist) about it and he sent me really good results where the iMac pro was really delivering with an eGPU Radeon VII.
I haven't been able to replicate this performance. 2GPUs is not faster than one GPU, and the Radeon VII is not faster than the internal GPU.
When using both GPUs they don't reach 100% usage according to Activity monitor / iStats Pro.
I am wondering if it could be an enclosure issue -I've had the same findings on my assistant's 6-core iMac...
I'll post my findings.
@guillem_g, Did you ever figure this out? I’ve had a Radeon VII since release using it with my Razer Core X Chroma attached to a MacBook Pro 2018 (max spec) for use with Davinci Resolve and I saw practically no increase in performance as I’ve seen benchmarked online.
Radeon VII has basically ended up being used for gaming on an external bootcamp partition.
Would like to figure out how to fix this issue for my professional workflow however.