Mac mini 2018(i7 3,2GHz) + eGPU + low buffer performance

Discussion of music production, audio, equipment and any related topics, either with or without Ableton Live
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Joined: Sat Aug 13, 2005 6:56 pm
Location: Norway

Mac mini 2018(i7 3,2GHz) + eGPU + low buffer performance

Post by aukleive » Tue Sep 03, 2019 7:39 pm

Just thought I would share this, after almost ditching this 2018 Mac mini - almost tearing my hair out in frustration.

This buy was meant as a sort of backup or redundant? machine for live shows. After much googling and countless tries still It proved impossible to downgrade Osx to El Capitan (or anything else, for that matter), so I was stuck with Mojave. Not happy. My existing setup works flawlessly on a MBP 15 running El Capitan (mid 2014, i7 2,5 Ghz, using the discrete buildt in GPU - EXCEPT for the cooling fans making quite some noise. A little too much for extremely dynamic recordings or high gain condensers nearby , and I needed a clone of this exact system. Not possible, neither via Time Machine nor external (usb or thunderbolt) boot disk - OR anything else.

So I installed every single thing from scratch, while ensuring everything was 64-bit.
(File vault is off, and security settings is on low and allows booting from external media)
No WiFi and Blutooth on.
Hardwired usb-keyboard.
Apple TB3 to TB2 adapter, to Presonus Quantum. The second TB2 port on the Quantum is connected to an old Belkin TB(1) Expressdock - which again has diverse inputs from disks, midi over usb, ilok as well as a DSI Pro2 (NRPN mode via Soundtower plugin) and a Push2. No problem at all with the traffic, since the Quantum under stress just uses 2% of the available bandwidth of TB2. So all this to one MacMini TB3 (usb-c) port.

Connected via HDMI to a LG 27inch 4k external screen (Apple claims support for 3 of these, I think) Ableton 10.1 was unable to do almost anything with a buffer size of 64 (44.1 kHz). I need this low latency being a percussionist/drummer playing through diverse transformative VST´s running in Live.
Using the application QuickRes to downscale to nonHiDPI resolution 1980x1080 made things better, but still seriously underperforming. Shit, I think even my old MBP 13-inch 2011 did a hell of a lot better!!

Still really needing/wanting the extra horsepower from the 3,2 GHz cpu (so I could maybe use a couple of more instances of Flux Spat v3 verbs for surround and the like) I read up on, AND ordered (from Applestore), the Sonnet Breakaway Puck Radeon rx 560. The cheapest one, since I'm not a gamer and reckon´Live doesn't need so much power.

Connected with a 2 metre Belkin TB3 cable, also from Applestore: Flawless plug and play with Mojave 10.14.6!

Practical A/B tests:
Live 10.1. Presonus Quantum TB interface. Buffersize 64. Live´s Reported overall latency (44.1) 3,45ms. Very playable indeed!! (when it works without glitches)

Using the MM´s inbuilt gpu, I could only load ONE instance of Serum (Preset: PD ArticWind [CFA], NB! Voicings reduced from 16 to 4). Even when reducing voicing down all the way to Mono!!! - would still make audio "crackle" (like it normally sounds when the buffer size is too low)...
Meaning: Unusable for tight playing, and full of disturbing digital garbage.
CPU-use 13-15%

B) Hooked up the Sonnet Puck.
I could now load 13 instances of the same preset, but now with 4 voices each, and No crackles!! Totally playable indeed!!
We are now talking 13 times 4 voices.
So we have sort of 52 times the "performance". In a practical sense this is true in this example. 52!
CPU-use 37 %

I did try a microphone input also, had 4 plugins on the track (FabFilter Pro Q3, Soundtoys Crystallizer, Flux Spatv3, Kush UBK 1)

Inbuilt cpu could again NOT PLAY ONE TRACK.
With the PUCK I managed 47 equal tracks!!!!! Thats 188 quite hardcore plugins!!
CPU-use 33%

The cooling fans on MacMini can hardly (if at all) be heard, and the same goes for the Puck.
Seriously silent so far. There is a slow fan running on the Puck, but I have only heard it make some more noise a couple of times, but only when turning on the whole system - and then silent when working with Ableton.

My 2014 MBP is no slouch, but this beats it hands down. And no noise (so far). The MBP would howl....

Final fact: There will be crackling when resizing Ableton window. So there is some issue there; cooperation Ableton/Mojave/gpu/cpu. But I normally do not resize anything when playing a live gig, so no real big problem - WITH the PUCK.

Without is a total disaster!!

NB! MM has only 8Gb´s of RAM on these tests. 32 Gb on its way by snail mail. Doesn't look needed though, as I still have about 3 Gb free when Live is running.

Audun K

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Re: Mac mini 2018(i7 3,2GHz) + eGPU + low buffer performance

Post by the13thour » Wed Sep 18, 2019 11:08 pm

wow, this is great! Thanks for sharing! I'm at the end of my rope too with my new mac mini. Glad i found this. I'm running two 1080p monitors that are not 4k. Do you think that makes a difference vs 4k? I'd rather not have to buy an external graphics card unless i have to. :/

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Joined: Wed Oct 24, 2007 4:50 am

Re: Mac mini 2018(i7 3,2GHz) + eGPU + low buffer performance

Post by fishmonkey » Wed Sep 18, 2019 11:42 pm

i started using an eGPU with my MacBook Pro a couple of months ago. totally sold on it and wish i'd invested in one earlier!
badbrainz wrote: I'm a drummer, so I'm already at an intellectual disadvantage here

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