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GPU Card recommendations for an eGPU

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So I am finally going to try and sort out my display setup and could do with some advice.


Current set up :


MacBook Pro 16" with LG 5k and LG 4k displays.  Blackmagic eGPU (Radeon 580)


I get a lot of crashes in VWX when working on the 5K display and a heavy file with lots of geometry.  I suspect the card / Vectorworks just can't handle the resolution.  It doesn't seem as bad when just using the internal display and no 5k monitor connected..  I may be wrong - but I need to do something to fix this.  I have seen other people on the forum (  @JRA-Vectorworks-CAD @RonMan in particular have had success with non Blackmagic eGPUs)


Added to this - the Blackmagic eGPU does not output enough power to charge my MacBook Pro.   Apple recommend attaching the 96W power supply as well as the eGPU.  I have also seen benchmarks showing that the Radeon 580 in the Blackmagic is far outperformed by other cards that are cheaper.


I would rather keep my two LG monitors - but as they are both Thunderbolt 3 / USB-C - it limits me massively on which eGPU I can use.


So I thinking of ditching it all and buying :


- Razor Chroma eGPU (this supplies 100W to the MacBook Pro)

- Either Radeon RX Vega or Radeon WX 7100

- Then a 4k matt monitor - (why are glossy monitors so common?!).  I assume the best would be displayport?


Keen to get any recommendations on which GPU card is best or is it much of a muchness?  Big problem I have us that when I search for either Radeon RX Vega or Radeon WX 7100 I seem to get a long long list of cards - all at different prices, and with what seems to be a minor difference in specification.


Not to mention how I install a webcam / microphone / speakers - which I use a lot for video conferencing.


So confused!

Any help much appreciated - can't keep working with these crashes. 



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Ten minutes ago I had the first crash I have had in days. I use the Razor Chroma X eGPU and the Radeon WX7100. This is a very good combination, but make sure your monitors can handle display port. If they cannot consider a different card in the WX series. The less and greater models feature mini-display port. The faster one is not worth the money in my view, and the slower one does not have the power. Note the Radeon WX series are workstation cards, not gaming cards. I would NEVER use a gaming card for CAD work. The optimizations are totally different.


The crash-dump is not as clear about the cause. There was a EXC_BAD_ACCESS (SIGEGV) fault. These are usually a code errors. It looks like VW tried to access something that was no longer there. I was designing a space craft (don't ask), changed views to move something, touched it, and boom! The object was real but VW lost track of it.


I won't say I have never lost an object while programming, but I usually can find and fix it. The problem VW has is they have no idea which object I created, or where it was. Either the rendering engine or the user interface lost track of the object.


After all that BS, I still believe the Razor and the Radeon WX7100 are a great combination. I did have to get rid of my Apple Thunderbolt displays (I loved them, but they are old and available in Dallas). I would like to hear from others on which eGPU and card they are using. I think the Mac Pro would kick ass, but I don't have the cash to buy a used Ferrari, let alone that rocket.

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Hello again


So - the other night I was working on a 3D model into the evening.  I wanted to be in the same room as my wife - so I unplugged my Blackmagic eGPU and worked away just using the built in screen.  VWX worked well.


The next morning, I went back to my desk and plugged back into the Blackmagic eGPU and carried on working on the same model.


Immediately I noticed the difference in performance.  But not as you would expect.  Working on viewport annotations on a sheet layer, with the eGPU plugged in, was unusable.  I had been doing exactly that the night before using the in built GPU (admittedly a good GPU - 8GB Radeon Pro 5500M with 8GB) but I did not expect worst performance with the Blackmagic / Radeon 580 8GB GPU.  


I was in a rush at the time - so just quickly unplugged the GPU and went back to using the monitor on the laptop to finish what I had to get done - but I was surprised at the poor performance.


Now I have a little time on my hands, I have just been doing some experimenting.  A few days prior - I had turned on the "Prefer external GPU" option in the Info pane you get from right clicking on VWX 2020 in the finder - with an eGPU attached. I assumed that would be worth doing.


But having done some experimenting it seems that that causes some issues.  I found that with the "Prefer eGPU" setting selected - when using VWX on my 4k monitor (which is plugged directly into my Mac) - VWX slows massively.  Activity monitor GPU graphic oddly says that none of the 3 x GPUs are being used.


Moving VWX to my 5K monitor (which is plugged in to the eGPU - then the Mac) and VWX works much better.


Without the "Prefer eGPU" option selected - I don't see this issue.  VWX uses the build in Radeon 5500M when on the 4k monitor, and the eGPU when on the 5k monitor - as you expect.  Performance is good.


Will leave that check box deselected from now on - must be a bug somewhere - maybe with OS X?





Screenshot 2020-03-01 at 12.59.25.png

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It took me a moment to get your setup. One monitor is directly connected to your Mac while the other is on the eGPU. Yes, that will cause a problem depending on where you have the control bar in the Display/Arrangement setting in System Preferences. 


If at all possible put both monitors on the GPU and set the control bar on one of the eGPU monitors. You can determine what is running where by using System Activity and selecting the GPU tab. You can then see what is running where. 


I hope this helps.

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Thanks RonMan


Yes - the Blackmagic eGPU only has 2 x Thunderbolt 3 connections - one goes to the Mac, the other to the monitor.


It does have an HDMI out too - but I don't have an HDMI monitor - just two Thunderbolt 3 monitors - so one monitor is directly connected to my Mac.


Wish there was a GPU card, which I could put into an eGPU with 2 x Thunderbolt 3 outputs...


Thanks for all


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In daisy chain mode, as shown, the Mac GPU would be hard pressed to keep up. If the daisy chain has the eGPU before the MacBook, you would get all gate benefits of the eGPU. I think that is the ideal configuration. If you can't daily chain,  there is a way to make the eGPU primary in System Preferences. Go to Displays/ Arrangement and make sure the menu bar is on the display from the eGPU. You won't need to change the setting in Get Info. When you use the system by itself, the internal GPU will take over, but whenever you use the eGPU, you will get the eGPU performance by default.


The only time I use the internal GPU is when I am traveling. Otherwise, I drive everything from the Radeon Pro WX7100. Here are some test results


Using GeekBench 5.01, OpenCL test

  •  40,336 AMD Radeon Pro WX 7100 Compute Engine, eGPU
  • 13141 AMD Radeon Pro 560X Compute Engine, internal

Using GeekBench 5.01, Metal test

  • 45,878 Radeon Pro WX 7100 Compute Engine, eGPU
  • 14,031 AMD Radeon Pro 560X Compute Engine, internal

The difference is easy to see when using VW. Both monitors are Dell UP2716D models. They have excellent color. The resolutions are 2560 x1440. There is an equivalent 4K model. Of course it costs more.


I think that is all I have. Forgive and spelling for grammar errors. I slapped this together in just a few minutes. I did run the GeekBench tests again for this.

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Hi again - 


So helpful - thank you!!!


@PeterYip  Tried both of those with no success I am afraid.  I seems the LG 5k only has one TB 3 input and the remaining USB-C sockets are just USB.  Also tried the HDMI to USB-C adapter route with no success.


Will probably wait until there is a GPU card which I can install in a eGPU which has at least 2 x TB 3 outputs.  My only other choice is to put the whole thing on eBay and buy a couple of Displayport monitors.  Again - the Blackmagic eGPU doesn't give great graphics performance.


@RonMan I do a lot of Skype calls - do your monitors have a webcam?  In fact - how can you do USB Webcams / Mics / Speakers with an eGPU?  🤯🤯🤯🤯


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@Andrew Davies Did a little read on the spec, as I have been interested in getting the eGPU pro. It seems it might be possible with a docking hub.



might be worth asking Blackmagic about how to go with this, I use to work with a lot of their equipments, their technical support are not bad.



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The monitors do not have speakers or cameras. I got better monitors at a lower price because of it. I use an external speaker at my desk and the camera on my laptop when I need to do Zoom or Skype. I have a OWC Thunderbolt 3 doc that I use for just a couple of things. I only use it for GB Ethernet and my SpyderX. There are 4 extra USB ports if I need them. I could put a camera on it. Everything else goes to the eGPU, Razor Core X Chroma; two mice and my 3Dconnexion Space Mouse. I have a Logitech G700s for normal use, and a Razor Naga Trinity for VW. I program the mice with the SteerMouse preference panel.


I did not choose the BlackMagic eGPU based on cost and comments from others. The Core X Chroma is great, but the GB Ethernet port does not work well on Windows, and not at all on a Mac. I decided to keep it after getting everything set up. I already had GB Ethernet from the OWC dock. The AMD Radeon Pro WX 7100 came up because it was supported and AMD recommended it for VW (on Windows, but who cares about Windows). I would have had to spend another $300-500 to get a better card from AMD. You saw the performance in my previous post. I'm doing OK.


One thing I did learn, you can get battery swelling if you use your system with a dock most of the time. I got the battery replaced (three days without a computer–it was hell). Now I have it on a laptop stand that has a USB fan underneath. I found it at Fry's or Staples years ago. This is a great use for something that to gather dust previously. The temperature of my MacPro is down 5-10 degrees. The battery should not swell again.


There is a 34 TB NAS in the cabinet along with a UPS for it. My wife might disagree, but this is a simple layout.


The monitor you might consider is the Dell UltraSharp 27 4K Monitor: U2718Q. It comes in a 30 inch version as well. A webcam is $50, and you likely have speakers laying around somewhere. 


I recommend you try Geekbench to see what kind of performance you get in different setups.

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