Buying Razer Core X eGPU enclosure. Evaluating Radeon graphics cards

I have an iMac Pro 2017 with Radeon Pro Vega 16GB built-in graphics and 64GB RAM.
I’m trying to run a second HD monitor and process Video AI tasks. Crashing and burning everytime I push past 50% memory. I’ve done some research on the various options and besides video processing, the iMac works great. And I don’t need a new M2 laptop, so eGPU seems like the most cost effective solution, given that Apple encourages it.

I don’t think I can go wrong with a Razer Core X enclosure. It’s the choice of video cards that has me asking for some expert advice. The only card option I have is Radeon, but they have a wide variety to choose from, making it a challenge to find the right mix. Given the enclosure costs the same price as a halfway decent GPU, I figured I wanted to put something in that really supports what I need, primarily video processing. If I’m not using Topaz Video AI, I’m editing in FCPX. In need some raw video processing power at an affordable price.

Tom’s Hardware has the a great summary Toms Hardware GPU Benchmarks 2023.

Here are some relative price/performance points from this.

~35fps using RX5808GB @$125 or $3.57/fps with 8GB VRAM
~80fps using RX6650XT @$400 or $5.00/fps with 8GB VRAM
~110fps using RX6750XT @$550 or $5.00/fps with 12GBVRAM
~120fps using RX6800XT @650 or $5.42/fps with 16GB VRAM
~140fps using RX6950XT @1000 or $7.14/fps with 16GB VRAM

That seems to suggest a sweet spot around the 6600 or 6700 family processors at $5/fps.

Looking the specs, it seems like most important variables are:
-Process Node
-GPU Cores
-Ray Tracing Cores
Tensor Cores

I would love to know anyone’s experience using an eGPU, and had at least one of these cards in it and what you think in terms of performance and cost.

Thanks in advance! I’m leaning towards the RX6750XT at this point, given current pricing.

Hold up… I just spotted the RX6950XT @699 on
That clocks in at 4.999/f/s and a reasonable buy forward at that price.

No matter what GPU you buy it won’t get faster because the CPU is limiting here.

Also on the net you can read that an egpu for FCPX does not help and that the internal gpus are faster.

And the benchmarks you look at in thw are all for gaming.


I have never heard of anyone using an eGPU on a mac. Do they make drivers for mac? My impression of macs in general is that you cannot put whatever hardware you want in them because of the lack of drivers… and Apple worrying about inconsistent user experience from unsanctioned hardware—therefore no drivers are ever made for most hardware that is not already in macs.

Apple Support-eGPu

Ah, so it’s limited to AMD GPUs and not the latest generation yet. Thank you.

Bingo. You’re right, the Tom’s test benchmarks were for rendering 1080p and 1440p video, which I thought would be a relatively good proxy for general GPU performance.
Where things get murky quickly is what Topaz uses for its rendering algorithms. You’ve got shaders, ray tracing, and tensorflow processors. What gives you the biggest bang for your buck in Video AI processing?

My iMac has a 3 GHz 10-core Intel Xeon processor. CPU performance has never been a problem. The problems come when I attach a second monitor and try to do anything else requiring GPU - transcoding, rendering, anything that adds a load to the GPU ends up with a “lights-out” system shutdown. When I reported this to Topaz, I was told to reduce max memory usage to 35% and start there, working my way up to see how far I could push it without crashing. That’s been a frustrating experience and requires I shut off my second monitor (useful for video editing) and run any rendering as a dedicated workflow which kinda sucks.

That’s interesting about FCPX. I’ll have to dig into that. I suppose it would depend on whether FCPX’s dev team has optimized for eGPU or plan to in the future. Most people probably won’t remember this, but in the early days of Macintosh, post-Lisa, the Motorola processors just weren’t competitive with WinTel, so there was a company that made a bunch of add-in accelerator cards that boosted CPU/GPU performance by quite a bit. Can’t remember their name, but most Mac owners looking for peak power bought them. That market only lasted about eight years until Intel became the processor of choice for Apple (circa 2005?), but they made a huge difference. Rather ironic we’re seeing this play out again for Apple…