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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Current Status of eGPU on Macs

Steve Sherrick

Steve Sherrick

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Looking for real world feedback of how how eGPU enclosures are performing as of today on both TB2 and TB3 Macs. A 25% increase in performance for example, would actually be huge for one of my systems right now as it’s right on the edge of capability for exporting UHD 29.97 timeline in Resolve. Akitio, Bizon, etc all have solutions that have been out in the wild and I’m curious if anyone has hit a homerun with a particular combination of hardware where they have significantly improved the system’s performance over it’s bare configuration.

I’m currently looking at PC, Linux, Hackintosh, and eventually the 2018 Mac Pros to run Resolve UHD and 4K sessions. Biding my time until all of my research is complete.

Thanks!
 
Steve Sherrick said:
Looking for real world feedback of how how eGPU enclosures are performing as of today on both TB2 and TB3 Macs. A 25% increase in performance for example, would actually be huge for one of my systems right now as it’s right on the edge of capability for exporting UHD 29.97 timeline in Resolve. Akitio, Bizon, etc all have solutions that have been out in the wild and I’m curious if anyone has hit a homerun with a particular combination of hardware where they have significantly improved the system’s performance over it’s bare configuration.

I’m currently looking at PC, Linux, Hackintosh, and eventually the 2018 Mac Pros to run Resolve UHD and 4K sessions. Biding my time until all of my research is complete.




Thanks!
Click to expand...

+1 here.
 
I have seen those benchmarks, but just trying to get some real world feedback from fellow users who will probably be running some similar tasks that I do. Reliability, workarounds, do's and don'ts, etc.
 
Steve Sherrick said:
I have seen those benchmarks, but just trying to get some real world feedback from fellow users who will probably be running some similar tasks that I do. Reliability, workarounds, do's and don'ts, etc.
Click to expand...

Real world performance....

First of all nVidia GPUs are said to get support soon, but nothing official yet. Some support has shown in certain developer beta driver sets and same with OS 10.13 releases. Unfortunately, the only nVidia cards that are working are those with a modified BIOS to add specific OS X support.

Beyond that, assuming your eGPU enclosure can fully support your desired card, we have to accept the limitations of the Thunderbolt / PCIe bridge interface. Thunderbolt 3 ports are 40Gbps capable, but that is not always the case here. TB3 exists as either single or dual ports per header. The dual header is backed by 8 lanes of PCIe v3 and can supply either of the ports at a full 40Gbps of PCIe bandwidth, but not both at the same time. A single TB3 port is backed by 4 lanes of PCIe v3. 4 lanes = 3.94 GB/s which actually translates to 3.88GB/s after the 128b/130b transmission overhead. What that means is you have a real world 32Gb/s to work with and not the 40Gb/s advertised.

Don’t take that as a bad thing regarding the available bandwidth, that is the bandwidth of a PCIe v3 X4 slot.

Most all current GPUs are PCIe v3 X16. Only the latest, most powerful ones really utilize all that bandwidth and even then, only for large memory dumps, loading data sets to onboard memory, stuff that’s pretty darn quick and not computationally demanding. For computational tasks the X4 bandwidth is going to be fine in many cases. Typically the more complex the computation and longer it takes, the less of a bottleneck the PCIe interface. Some operations that the GPUs have become very good at handling like Bayer pattern processing, it’s possible for that X4 interface to become a bottleneck. Although, the bulk of computations people in this community are likely to run are not going to be an issue as long as current GPUs are kept to one per TB3 port.

The biggest hinderance to eGPUs is latency. For me the eGPUs feel sluggish for initial response. But once everything is transferring and flowing along, you’re fine, not a big deal that it took a handful of milliseconds longer to get started. If the software is not well suited to deal with this or you’re dealing with large data sets or evolving / real-time frame data that has to be loaded in and out of the GPU frame buffer from the PCIe bus, this can be a significant performance suck.
 
Also, with eGPU editing software like Premiere does not support multiple GPUS in the same way a game engine or a 3D rendering engine like Redshift does. So with Redshift if you add in a second GPU you get x2 the power and so on. With an editing program like Premiere you will hardly see a difference- 10% etc etc- same with Final Cut Pro.
 
Steve Sherrick said:
Looking for real world feedback of how how eGPU enclosures are performing as of today on both TB2 and TB3 Macs. A 25% increase in performance for example, would actually be huge for one of my systems right now as it’s right on the edge of capability for exporting UHD 29.97 timeline in Resolve. Akitio, Bizon, etc all have solutions that have been out in the wild and I’m curious if anyone has hit a homerun with a particular combination of hardware where they have significantly improved the system’s performance over it’s bare configuration.

I’m currently looking at PC, Linux, Hackintosh, and eventually the 2018 Mac Pros to run Resolve UHD and 4K sessions. Biding my time until all of my research is complete.

Thanks!
Click to expand...

Have not tested my self but from reading the Akitio is what I would drop my money on. I use their PCIE TB2 enclosures both for fiber and 4k BM card and it works without hiccups. Sure not the same data rate but if the TB3 stuff would work just the same then you should not have any issues.
 
As a bit of info, I'm working through a color grade on an ultrabook with a Kaby Lake-R processor (quad core) and 16GB ram (which I plan on upgrading to 32 soon). The built in dGPU is an NVidia m150 with 2GB of GDDR5, and I have a Razer Core connected, with an NVidia 1080Ti in it. I'm getting pretty smooth playback at quarter resolution with 8K Helium footage with this setup.

The built in dGPU isn't powerful enough for more than 2K, but it is able to run Resolve reliably.

One note: having Resolve use both GPUs doesn't work at all well, because Resolve wants the GPUs to be symmetrical, so it constrains the 1080Ti to 2GB if they're both enabled, instead of its actual 11GB. I haven't tested rendering with it yet.

Another note: it helps to connect an external monitor to the 1080Ti and set that is primary. That puts Resolve on the external graphics card instead of the internal.

In case anyone is wondering, the machine is an HP Spectre x360 15".
 
Jarek Zabczynski said:
I'm waiting for the day we can connect like 4 eGPUs together and have a beastly workstation.
Click to expand...


That would be pretty cool. I've been eyeing the HP ZBook x2 partly because it has two Thunderbolt 3 ports on it. :)
 
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