Cycles Render using AMD Radeon RX570

Hi Friends,

I have one MacBook Air 13’’ (2013) and my graphics card Intel HD Graphics 5000 1536 MB doesn’t work with Blender (driver bug). Ok, I have to Render with my CPU that have low performers. Because of that, I have bought one eGPU:

eGFX Breakaway Puck Radeon RX 570

To see the difference of speed:

Ok, very good !!! Awesome improve for what I have…

I have set up on User Settings:


Sample: Using one simple cube with some lighting

Using CPU I get the render Time: 11:34.51:

Using GPU I get the render Time: 09:49:37.24:

WHAT!!! With eGPU is more slower… slow … slow … slow

What is wrong here?​

Many thanks
Best regards,
Ricardo Figueira

I am a little confused.

You are looking at the remaining time (which is almost never accurate) what is the actual render time for it to be finished?

Something is wrong with your render settings when it takes that long to render a simple cube.

Is not accurate but its not a big difference of the reality. I didn’t wait to finish on GPU because takes too long… on the CPU will render on that time.

The render settings are the same for both renders, I have only change CPU to GPU.

Render Settings:

The final render looks like this:

hmmm looking at your settings there are a couple things I would change (although I dont think it will make a major difference in render time, but it will help).

Seems like its something with your GPU (make sure drivers are updated) also you should change your tile size when rendering with GPU to 256x256.

Also just note that you have “square samples” turned on so you are really rendering at 1600 samples.

After looking at your settings though, there shouldn’t be that big of a difference in rendering time between the two. So I would say it has something to do with your GPU, maybe a more experienced hardware person can chime in and shed some light.

I just tested on my 2013 Macbook pro rendered a similar scene to yours and on CPU it rendered 1:58 at 1600 samples. (Dont have a GPU)

Best advice for both performance and compatibility with Blender (now and in the foreseeable future):

  1. Don’t use a Mac
  2. Don’t use an AMD GPU, use an NVIDIA GPU with CUDA

Apple insisted on developing their own crappy OpenGL/OpenCL drivers, then they dropped future support altogether in favor of their new Apple-exclusive API (Metal).

Mac OS is a terrible platform to develop for. It’s also not a platform that many professional users still use. To support it properly would mean exerting a disproportionate effort, which is unlikely to happen without material support from Apple. Any problems you will encounter are far less likely to get fixed as result.

To be clear, I’m saying that as a developer, not as an Apple hater. I generally like their products, but they absolutely dropped the ball on the professional market, even though they like to style themselves differently in their ads.

Second-best advice:

Try adjusting your tile size. Try one big tile covering the full frame. Try 512x512, try 256x256. Try a different version of Blender - I assume you are using the latest version?

No success here.

I have debug and found some problems with blender and I have reported on blender support:

I found on the log some problems:

  • Exception in module register(): '/Applications/Blender/’

  • I1117 10:39:31.867377 2518606720 device_cuda.cpp:2113] CUEW initialization failed: Error opening the library

DAM!!! :frowning:

The GPU is support by Apple:

Recommended Thunderbolt 3 all-in-one eGPUs:

* [Blackmagic eGPU]
* Sonnet Radeon RX 570 eGFX Breakaway Puck


I don’t know if I install the Windows 10 on bootcamp it will work… don’t know if this is a OSX driver issue or blender issue.

That doesn’t really help their crappy OpenGL/OpenCL implementations.

Try it, you’ll get to use the somewhat less crappy AMD OpenCL drivers instead.

If it doesn’t work on Windows, it’s probably an issue with the adapter.

Thanks for the reply. I have to return the package AMD Radeon RX570 and bought the GeForce GTX 1050Ti… its was amazing eGPU for all apps except for blender!!!

Dam… for my system its faster than the GeForce GTX 1050Ti … BUT I can’t use that speed on Blender… because of that, I return it! :frowning:

GeForce GTX 1050 Ti:

Radeon RX570: