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Mac Mini with eGPU.

apple_unreal

apple_unreal

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Original poster
Jun 15, 2020
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Hi

I have a 2019 Mac Mini maxed out, 64 ram and a external GPU, a Radeon RX 5700.

I see the benchmarks and the 16" MBP is probably as powerful as my machine, specially in the GPU side.

How they can have the same GPU performance in a MBP if the eGPU is so massive already?
 
The MBP is using either a 6-core i7 or 8-core i9 processor - what CPU is that Mac Mini using? Notebook GPUs have always been comparable to their desktop counterparts while also being smaller in size. For example, my MSI gaming laptop has a GTX 1660TI card with 6GB GDDR5 (non Max-Q), and it's within 5% of the desktop version when benchmarked.
 
At least in my eGPU, the majority of the volume inside the enclosure is empty space and the PSU.

I think that top-end MBP GPU uses HBM memory, which is more or less part of the GPU chip itself. Contrast that with GDDR, which is typically separate chips that need to be off to the side somewhere, so require a larger circuit board.

There's also the fact that GPU electricity/heat vs clockspeed is not linear. So when a GPU product's clockspeed is set at beyond what the actual efficiency sweet spot of the technology is, it uses a LOT more electricity/heat for only moderately more performance. Diminishing returns basically. Some Vega64 desktop cards would pull up to 400W alone and the reason for that was that AMD had to clock them way beyond their efficiency sweet spot just to get anywhere near the gaming performance of the contemporary NVIDIA cards.
 
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Does the machine do what you need it to do? If so, stop obsessing over benchmarks.
 
What score are you getting. I get this with my 2018 500GB 16Ram and using a Vega 56 eGPU.

Screen Shot 2020-07-15 at 5.27.50 PM.pngScreen Shot 2020-07-15 at 5.28.07 PM.png
 
IIRC Apple have pretty much abandoned OpenCL so it's probably not a terribly useful benchmark.
 
Are you using an external monitor with the eGPU? eGPU's perform better with an external monitor.
Maybe also try a different port, I've watched some videos that switching the port on the GPU may improve performance.
Also saw that having a second display may improve performance.

With the base model 13" Macbook Pro (with 8th gen cpu) and 5700 XT, Max Tech got a score of around 55,000 with Geekbench 5 metal 🤷🏻‍♂️

Also should note that an eGPU wont perform as fast as internal discrete graphics due to the bottleneck of Thunderbolt 3.
Thunderbolt 3 provides 4 lanes of PCIe , where as an internal would use up to the full 16 lanes.
 
Mizouse said:
Are you using an external monitor with the eGPU?
Click to expand...
My mini is connected to my LG 27UD58 with a TB3-DP cable. My eGPU is connected only to my mini's TB3 port. That's the only way I've been able to get things to work reliably (after months of trying different setups). So the eGPU is there just for the added graphics horsepower.
 
jayducharme said:
My mini is connected to my LG 27UD58 with a TB3-DP cable. My eGPU is connected only to my mini's TB3 port. That's the only way I've been able to get things to work reliably (after months of trying different setups). So the eGPU is there just for the added graphics horsepower.
Click to expand...


Read this thread where I talk about setup with the mini and egpu. Try that setup and test it out.

best-games-to-play-on-mac-mini-with-egpu.2232371
 
Sorry to hijack this thread, but does anyone know if you can connect 2 eGPU’s to a Mac mini?
 
jayducharme said:
I had tried that. I couldn’t get anything more than 1080p at 30 FPS that way. And the eGPU didn’t seem to be pulling its weight. My current setup seems to be working fine though.
Click to expand...
Connecting the monitor to the mac mini instead of the eGPU means the data has to do a round-trip back into your mac mini. This is always going to be less efficient.

There is an eGPU penalty on framerates that is also somewhat unavoidable. Counter-intuitively, the penalty vs. an internal card is less at higher resolutions.

You will never have worse performance vs. an internal card than running a monitor not attached to the eGPU at 1080p
 
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With the imminent release of Octane X (gpu rendering on AMD gpu’s for those who wonder), I was looking at the possibility of this compared to a 2019 Mac Pro.
 
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