Cycles performs ULTRA slow with egpu vega 64 (Saphire Nitro)

HELLO community, i have a problem using cycles with vega 64 in an egpu on mac os.

Just tried using cycles in blender 2.97 with gpu compute from my new vega 64 nitro from saphire in a new mantiz venus external enclosure. The render speed in cycles is horribly slow. Its like 4 time slower than my cpu from mac mini 2018 with 32gb ram and os mojave.

Anyone has a clue how to fix this? I spend over 1000 euro to increase cycles render performance but now i am only stuck with an egpu that is 4 times as slow as my half sized mac mini next to it. All benchmarks i saw before where great even though i think they might have been not tested on macos. I could cry. Help! Any constructive hints?

I tried looking up solutions everywhere, and found similiair reviews all around. like in this thread: https://developer.blender.org/T53795

quote:
‘Im using an 8 core iMac Pro with Vega 56 and latest version of Blender.
Cycles GPU rendering is totally unusable. BMW benchmark takes almost 2 hours to complete. However, using AMD ProRender engine, Blender GPU rendering is very fast. […]’

also i noted that it seems that blender officialy stated that OpenCL support for mac is dropped last year: https://lists.blender.org/pipermail/bf-committers/2018-December/049695.html

So does this mean there is no hope for using Cycles on Mac with an eGPU anymore?
What could i try isntead?

I tried using Radeon ProRender instead, which seems to render very fast with promising results, but unfortunately it is very clunky when using viewport render shading. In Cylces it was possible to drag meshes in another viewport fluently, while another viewport updated the render. In ProRender this seems not to be possible on my end. it is super laggy nad in complex scenes almost unusable. Am i doing something wrong? tried all setups possible. Also Material sahding doesent nearly show any colors or materials, which makes composing a super pain.

I would be super greatful for any advice that would help me get Blender running stable wit my Vega 64 egpu on mac, because i really dont want to drop using Blender :frowning: I jsut need a compatible node based/supporting renderer that works! :rofl: