Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.
Download on the App StoreAudiobus is the app that makes the rest of your setup better.
(NO, I'm just dumb...) iPad pro 12'9 (2015) still WAY BETTER than iPad pro 10'5 (2017) !!!!
Hi,
Quite crazy, but I just received an iPad pro 10'5 (2017) because I was really going "red" with AUM on my synths (peaks at 131%, and some lags) with my "old" pro 12'9 (2015) but it appears that the new one is way more laggy !
I've got peaks to 171% directly while opening an AUv3 synth (like Model D) and it's sooooo noisy...
Without moving anything, I've got 18% less CPU usage, which is great, but I can't switch apps without lag at all...Nor opening anything without glitches...
I don't get it, my only thinking is that the GPU on old 12' makes a huge difference with the new 10'5.
I can tell you that It's not an hallucination at all...
I'm returning this brand new 10'5 that is just useless to me...A bit sad...I guess the 2017 12'9 should really solve my problem...Hopefully...What's your thinking guys ? 
Comments
Which versions of iOS are you using?
I can play 3-4 instances of Model D into AUM running by Rosetta ... but when I open the UI from any Model D I confirm that behavior on the iPad 10.5 IOS 12.01
When I’m running the same setup on an iPad Pro 12.9 2017 it’s quite the same ... but I think the reason for this behavior is Model D himself
.
When I running the same setup with Arturia iSEM , Sunrizer and Syntronik I have no problems opening all the UI without any crackle or extreme peaks.
I’m afraid that the situation will be not better at an iPad Pro 12.9 2015 😎
I can understand your exaltation at your discovery but from experience no 2 ipads are the same unless you restore them from the same backup...and even then you might find different performance.
I've had 2 exactly the same air 2s and one had glitches and the other didn't, even with exactly the same audiobus presets. Don't ask me why that is as I haven't got a clue but have a hunch that even the brightest coding minds here might struggle with it. Variables for you.
Maybe it’s the combination AUM & Model D what created so high peaks. When I’m running 3 Model D within Cubasis the whole situation is much better. I can switch between the tracks, open the GUI and tweak the sounds without problems, crackles and peaks... 😎
Just wait for the new iPads presented on October 30th they have a processor A12X and 8Gb ram so they'll crush the Pros from 2017 that only have A10Xand 4Gigs of ram.
Ok...I'm dumb...
I tried to restore but couldn't from the previous iPad, so I used my presets from AUM+Modstep.
All was good, except that I forgot to check the latency into AUM who was originally 256, and on the new it was 128...
That explained everything...
So it's much better now...Not as great as I expected but at least I can finish my track now...
BTW IOS 12.0.1...
The new ipad will be quite expensive...I can wait a bit to see what's going on with all this USB thing before I dive...And let the price goes down a bit...
Thanks for all good testing and comments @greengrocer @supadom @chandroji @tja