eGPU performance beyond 2018

FilmCompos3r

macrumors newbie
Original poster
Dec 10, 2018
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Maybe a stupid question, but I’m wondering as Mac mini users if we’ll benefit from advanced GPU’s as they become available in the future, or if Thunderbolt 3 is already being maxed out in terms of bandwidth.

Specifically - eGPU benchmarks using Radeon or Vega cards are generally slower than their iMac Pro or even MacBook Pro counterparts. But when next generation GPUs come out, and we upgrade, will performance eventually surpass those machines?
 

F-Train

macrumors 65816
Apr 22, 2015
1,457
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NYC & Newfoundland
I think that what we are seeing is that certain applications and games and new technology like virtual reality are increasingly graphics intensive.

This means that graphics cards may have to become smaller, if they are going to fit in the small computers that people want*, and certainly more efficient.

Let's see what progress AMD's upcoming Navia series shows on these issues.

*The GPUs themselves aren't all that large.
 
Last edited:

Ploki

macrumors 601
Jan 21, 2008
4,103
1,398
I think that what we are seeing is that certain applications and games and new technology like virtual reality are increasingly graphics intensive.

This means that graphics cards may have to become smaller, if they are going to fit in the small computers that people want*, and certainly more efficient.

Let's see what progress AMD's upcoming Navia series shows on these issues.

*The GPUs themselves aren't all that large.
Even if they become smaller, bandwidth will not likely shrink.

Hypothetically you could connect a single enclosure to two TB ports to get double bandwidth, kinda like with screens.

Maybe a stupid question, but I’m wondering as Mac mini users if we’ll benefit from advanced GPU’s as they become available in the future, or if Thunderbolt 3 is already being maxed out in terms of bandwidth.

Specifically - eGPU benchmarks using Radeon or Vega cards are generally slower than their iMac Pro or even MacBook Pro counterparts. But when next generation GPUs come out, and we upgrade, will performance eventually surpass those machines?
I don't think that's true. BlackMagic eGPU Pro Vega 56 should outperform all the MacBook Pros, even the Vega 20.

I've seen iMac Pro benchmarks that outperform the internal GPUs mostly due to thermals, and MBP 15" is worse - since both systems have shared cooling for CPU and GPU.

I mean, obviously GPU directly to 8x PCIe lanes should be a little faster, but in iMac Pro and MacBook Pro 15" both are constrained by the thermals.
If you haven an eGPU, CPU has all the air it needs to breath and eGPU has its own air.

As it is now, a good eGPU setup should outperform the complete stock Mac line-up, which is fine. Mac Mini probably has a longer life expectancy and relevancy due to replaceable components.

i.e.:
MM 2018 i7/512GB/8GB/10GbE 1599$
- trackpad/mouse+keyboard ~250$
- 32GB RAM (Aftermarket) 200$
- Razer Core X(or v2 forgot which is cheaper) + Vega 64 8GB = total 700$
- Ultrafine 4K 650$
== 3300$

and with this config you can get away without having a dock... with the MBP, not really.

MacBook Pro i9/512gb/32gb
== 3849$

Mac Mini i7 already performs better in terms of CPU, and if you task both the GPU and the CPU, the gap will widen since the i9 will throttle below base frequency when the dGPU is under a lot of stress.

MacBook Pro is portable though.
 

Spytap

macrumors regular
Oct 8, 2010
121
69
if Thunderbolt 3 is already being maxed out in terms of bandwidth.
This is the part I'm interested in as well. Is there a point in the near future where New Card X and its successive card New Card Y the next year perform the same in an EGPU enclosure because Thunderbolt 3 is bandwidth limited?
 

Ploki

macrumors 601
Jan 21, 2008
4,103
1,398
This is the part I'm interested in as well. Is there a point in the near future where New Card X and its successive card New Card Y the next year perform the same in an EGPU enclosure because Thunderbolt 3 is bandwidth limited?
direct link from thread i linked up earlier.
https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_PCI_Express_Scaling/4.html
Thunderbolt 3 has PCIe 3.0 x4.

https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_PCI_Express_Scaling/25.html

its probably gonna happen in the future yes, but by that time you're probably have aging components on all other subsystems as well.
 

Ploki

macrumors 601
Jan 21, 2008
4,103
1,398
Here's what System Information says on PCIe lane width for a Vega 56 in an Asus XG Power Station. The assertions made in the Reddit discussion do not jive with what System Information reports:


View attachment 811179
That's impossible tho, the mini only has total of 16x lanes to begin with, 4x being used for drive, and thunderbolt 3 uses 4x lanes per controller chip if i recall correctly.

Could you scoot over to "thunderbolt" section of the system report?
 
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