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ruslan120

macrumors 65816
Original poster
Jul 12, 2009
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I was searching for an answer as to whether it's worth getting an eGPU if you already have a powerful iMac.

Couldn't find an answer so I decided to do some stabilization tests and make a video.

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iMac (2019, 5K)
AMD Vega 48 + AMD Radeon RX 580 (eGPU)
Octa Core i9, 40GB RAM, 1TB SSD + 2TB NVMe over USB C

Final Cut Pro Stabilization - 13% faster
DaVinci Resolve - 6% slower


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iMac (2017, 5K)
AMD Radeon 575 Pro + AMD Radeon RX 580 (eGPU)
Quad Core i5, 8GB RAM, 1TB Fusion Drive + 128GB SATA SSD over USB 3.0

Final Cut Pro Stabilization - 11% faster


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Forum mods: Please let me know if this is considered valuable info or whether it's too much self promotion. Hoping to provide useful information rather than spam links. Thanks.
 
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Thanks. 11% seems not so much to put another power hungry box with fans on the table.

The step from 575 to 580 doesn’t seem so big. The used software only uses one of them or both?
 
Thanks. 11% seems not so much to put another power hungry box with fans on the table.

The step from 575 to 580 doesn’t seem so big. The used software only uses one of them or both?

Both. I was wondering whether Final Cut Pro is smart and splits the tasks between the GPUs. Verdict: Yes.

You could probably do better with [1] a better CPU (based on Activity Monitor it looked like the CPU was too slow (2017 quad core i5 with no hyperthreading) to shuttle enough data to the graphics cards), and [2] more RAM, to cache the data.

Great video! It's not common to find reviews of the 575X Radeon GPU! I see you use a External 2.5" SATA SSD, do you use it as the mac boot drive? How is it?

Thanks for the kind words! Not as the boot drive, but all files (including the FCP library & app) were on the SSD.
I bet it'd be even faster as a boot drive...
 
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Both. I was wondering whether Final Cut Pro is smart and splits the tasks between the GPUs. Verdict: Yes.

You could probably do better with [1] a better CPU (based on Activity Monitor it looked like the CPU was too slow (2017 quad core i5 with no hyperthreading) to shuttle enough data to the graphics cards), and [2] more RAM, to cache the data.



Thanks for the kind words! Not as the boot drive, but all files (including the FCP library & app) were on the SSD.
I bet it'd be even faster as a boot drive...
Thanks for the confirmation. I am curious because I also ordered the 2019 iMac with Fusion Drive. Is the fusion really that bad? App opening speed, boot up speed, exporting videos speed?
 
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Thanks for the confirmation. I am curious because I also ordered the 2019 iMac with Fusion Drive. Is the fusion really that bad? App opening speed, boot up speed, exporting videos speed?

Yeah. The spinning hard disk is really slow. there are a couple good videos on YouTube, I think by 9 to 5 Mac, where they compare the two.

Regardless, congrats on the purchase
Which size did you get? (asking because the 1TB comes with a small SSD but 2TB and 3TB come with a 128GB). and if you got the larger varieties you can set it up as two separate drives, use the 128 for apps and macOS, and plug in an external drive to use for all files and not really use the spinning hard disk part of the fusion drive.

[Edit]
Found the video:
 
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Thanks for this! It seems like every review and video out there deals with MBP or Mac Mini.
Any chance you can re-run the test with DaVinci Resolve? Seeing as how BMD and Apple are in cahoots on external graphics accelerators, I'm curious how optimized their software is.

I think that putting a VEGA 64 GPU in that enclosure will definitely improve your performance, as 575 isn't far behind that 580 that you're using

I've got a Vega64 new in the box under my desk, and every few days go back and forth on whether I should order an eGPU unit or post it on eBay. Hence my question above! If it shows a significant improvement over the 580, it'll be worth it.
 
Yeah. The spinning hard disk is really slow. there are a couple good videos on YouTube, I think by 9 to 5 Mac, where they compare the two.

Regardless, congrats on the purchase
Which size did you get? (asking because the 1TB comes with a small SSD but 2TB and 3TB come with a 128GB). and if you got the larger varieties you can set it up as two separate drives, use the 128 for apps and macOS, and plug in an external drive to use for all files and not really use the spinning hard disk part of the fusion drive.

[Edit]
Found the video:
I got the 1TB since it's 1TB is enough for me. I currently have a 2013 21" iMac with 1TB SATA SSD and I barely got more than 500GB of consumed storage. I will surely go with the external thunderbolt 3 ssd route. Thanks a lot.
 
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Thanks! Looking forward to it. :)

Ah, thanks for the reminder and for the patience, work's been a plateful. Currently editing the FCP + DaVinci Resolve on a faster iMac + eGPU video and hoping to release tomorrow. DaVinci Resolve + the 2017 iMac - day after or Thursday.

Here are the results:

iMac (2019, 5K)
AMD Vega 48 + AMD Radeon RX 580 (eGPU)
Octa Core i9, 40GB RAM, 1TB SSD + 2TB NVMe over USB C

Final Cut Pro Stabilization - 13% faster
DaVinci Resolve - 6% slower

Video coming soon. Top post has been updated.
 
Bad news. The 2017 iMac is an apartment residence computer and I was unable to get Davinci on it (even by booting from USB 3.0, it's surprisingly incompetent at running a full OS + eGPU).

If you're interested in the video of benchmarks on the 2019 (Vega 48) + eGPU that's still on the backlog. (also accepting sponsorships of USB C ssds to put macOS on it and boot the residence iMac from it...)
 
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