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mvsr

macrumors newbie
Original poster
Dec 12, 2019
16
14
I've got a 2019 iMac (i9, 72GB RAM, 1TB SSD) and my two Thunderbolt 3 interfaces (Quantum 2626 and Apollo Twin X TB) are not very stable in Studio One 5 or Ableton @ 44.1/64 samples. If I set up a simple drum loop, no CPU taxing plugins or anything, I'll start getting "Audio IO Overload" messages every so often - more regularly with the Apollo Twin X.

At 128 samples, the issue seems to disappear (at the cost of higher latency, of course), or I just haven't left Console running long enough to catch one.

With a USB 3 interface (MOTU M4), 64 samples does not cause the IO Overload error.

I'm wondering if there's anything I can do, if this is just the expectation with current Macs (T2 chip?) and Thunderbolt, or if it might be my iMac.
 

mvsr

macrumors newbie
Original poster
Dec 12, 2019
16
14
what happens at a basic rate 48/24bit or 96/24 or 32?
The overloads scale - 44.1/64 samples and 96/128 samples have about the same number of overload errors, 44.1/128 and 96/256 both seem to be pretty clear of the overloads.
 

rkuo

macrumors 65816
Sep 25, 2010
1,300
937
I've got a 2019 iMac (i9, 72GB RAM, 1TB SSD) and my two Thunderbolt 3 interfaces (Quantum 2626 and Apollo Twin X TB) are not very stable in Studio One 5 or Ableton @ 44.1/64 samples. If I set up a simple drum loop, no CPU taxing plugins or anything, I'll start getting "Audio IO Overload" messages every so often - more regularly with the Apollo Twin X.

At 128 samples, the issue seems to disappear (at the cost of higher latency, of course), or I just haven't left Console running long enough to catch one.

With a USB 3 interface (MOTU M4), 64 samples does not cause the IO Overload error.

I'm wondering if there's anything I can do, if this is just the expectation with current Macs (T2 chip?) and Thunderbolt, or if it might be my iMac.
Anything else sharing bandwidth on those thunderbolt interfaces?
 

mvsr

macrumors newbie
Original poster
Dec 12, 2019
16
14
Finally remembered to copy the entire error.

HALC_ProxyIOContext::IOWorkLoop: skipping cycle due to overload
Audio IO Overload inputs: 'QT4H257' outputs: 'QT4H257' cause: 'Unknown' prewarming: no recovering: no
 

mvsr

macrumors newbie
Original poster
Dec 12, 2019
16
14
Sounds like this issue: https://arstechnica.com/civis/viewtopic.php?f=19&t=1450519

Apple being Pro only in the marketing sense. :(

That's the confusing part - I can find many USB-related sound issues, and T2-related sound issues... but this iMac is having the issues over Thunderbolt and doesn't have the T2 chip.

I've got a new iMac on order to relegate this one for at-work duty, guess I'll stress test it when it arrives and if there's no improvement it's time to finally look at Windows.
 
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