The plain fact of the matter, at least as I see it, is that while Apple has provided a path for eGPUs where one did not formally exist before, they have not fully committed themselves to that path, as they tend to do with quite a few ideas and technologies over the years.
Unfortunately, I believe this is a cultural issue within Apple and I have no confidence that it will ever resolve itself to anyone's satisfaction. Exacerbating the issue are competing priorities with iOS versus macOS, for lack of a better description.
While I can (and have) composed spreadsheets weighing the merits of the Blackmagic eGPU, and now the Pro model, with a DIY solution, I think the sticking point for myself and others in this thread is that Blackmagic
and Apple chose to release these models late in AMD's GPU release cycle. Polaris 20 was not a significant jump from Polaris 10 and the just released AMD RX 590 gave us yet another refinement (Polaris 30). While the Vega 56 and 64 are better than they are given credit for here and in other forums, they already
feel old, even if they are only coming up on 16 months of age. I think this has more to do with the fact that they were not as competitive with NVIDIA's 10x0-Series GPUs as we would have liked, especially since they are really the only game in town for Mac users given Apple's embargo/blockade/Cold War with NVIDIA. The recent release of the 20x0-Series of GPUs is not helping with perceptions either, even if they are not as good as the tech pundits would have us believe. I am looking at you Tom's Hardware.
Thus, the BlackMagic eGPU at $699 feels more like a rip-off than it actually is once you evaluate the components needed to replicate it. We can all quibble about the price of the RX580, but having been researching for the past six (6) months what would be the best path for me to take, I have noticed that since the cryptocurrency insanity abated and AMD GPUs began declining in cost, that the price for an AMD RX580 with 8GB of GDDR5 has settled at $250
on average. Sure, New Egg and other shops have discounted them more and prices have fluctuated, but between $240 to $270 has been the price band on any given, non-Holiday Season day. So for purposes of
my opinion, I am stating $250.
After looking at the breakdown of the Blackmagic eGPU on eGPU.io -
https://egpu.io/blackmagic-egpu-review-apples-ultrafine-curse/ - the PSU specs stated are 400w, which equates exactly with one eGPU box, the Akitio Node. However, here I will take some liberty given that the Node only provide 15w of USB-C Power Delivery and not the 85w of the Blackmagic eGPU. Factoring that into the equation, I think and the next cheapest eGPU box that provides that amount of USB PD would be the SonnetBreakaway Box 550. The Node is currently $230.00 and the eGFX 550 is $300.00, which average out to $265.00.
The USB 3.0 hub in the Blackmagic is a bit better than the average, and more complex due to the way Blackmagic engineered their eGPU, so I will break it out at $35, if you were to buy it separately.
Total cost is $250.00+$265.00+$35.00, which gets us to $550.00. Given the engineering time spent on adding a Titan Ridge controller, developing the enclosure, thermals, implementing separate USB-C controllers, the ability to connect to a 5K Thunderbolt 3 display, sales/marketing/support/packaging and taking into account profit for Blackmagic, while acknowledging that buying the components separately also takes into account profit for the GPU, enclosure and USB hub vendors, a roughly 27% markup of the $550.00 above really makes the Blackmagic eGPU a decent value for those that have, want or need a 5K Thunderbolt display specifically, already use Blackmagic hardware, edit with DaVinci Resolve or find the convenience of unpacking the eGPU, plugging it in and going are worth its shortcomings and lack of ever being upgradeable.
The Vega 56 version, unfortunately, charges too high a premium when we look at its pricing given that is swap out the Vega 56 with the RX580 and on average, the Vega 56 is going to set you back $510.00 (I took the average of 12 cards from both New Egg and Amazon) and added to the $265.00 for the enclosure, which seem exactly the same PSU-wise and the $35.00 for the USB 3.0 hub, you are left with a grand total of $810.00, which means that when multiplied by 1.27 to account for the above items, which I think is fair considering the older RX580 based eGPU has most likely not recouped its R&D expenses yet, leaves us with a retail prices $1028.70. At the current price of $1199, the markup is 48%, which is excessive, given that the Vega 56 is not cutting edge, the engineering, while not amortized yet, is paying for itself and we are still faced with a non-upgradeable unit once its service life is over. It would seem that a price of $1049 or even $1069 would feel more appropriate, while still keeping the profit margin decent.
As it stands now, I can DIY my own eGFX 550 and a Vega 56 from MSI for about $710.00 minus the USB 3.0 hub.
Also, Sonnet offers the same bundle of the eGFX 550 and an MSI Vega 56 on their site for $699.00.
A decent RX580 offering can be had with a $220 Sapphire Nitro+ for $220 and the eGFX 550 at $300, making a $520 eGPU a worthwhile proposition, although I would say an extra $50 for a 2-meter active TB3 cable should be added to every eGPU, including that tiny rat tail that Blackmagic gives you.
The issue here, though, is still the cost. Especially for the Mac mini buyer. I would have to opine that a $250 to $350 fixed eGPU box similar to the Sonnet eGFX puck might gain traction in the market. For that to work, you are looking at some aggressive negotiation to try and get Apple to relent on allowing the RX560 back into its eGPU graces, which it expunged when it released 10.13.4. Also, to be a really worthy fixed eGPU, the truly creative company would give us a Vega 16 at $249 or Vega 20 at $349 along with 2-3 USB 3.0 ports, single GbE port, two DP 1.4 ports and a single HDMI 2.0 port. Now, whether this is possible and turning a profit are two different things. I am talking economics for anyone who wants or needs a decent, if not fire breathing GPU, to play games and give video editors a bit of extra oomph, plus those other odds and ends apps that benefit from an eGPU. This entails Apple doing a better job of integrating them into Mojave and better support from app vendors. I suspect 10.15 may give us a better path forward.
Bottom line, there is a market for eGPUs, but without a competitive and cost-effective GPU to light the path, the market is going to be moribund at best. The Blackmagic eGPU is not it. Perhaps Intel's Arctic Point will be that GPU.
Again, Apple provides solutions to a degree and then either loses interest or decides not to follow through on those less glamorous items that make computing viable and more productive for the rest of us. I am hoping that I am wrong.
