Higher than expected latency with Ultralite MK5 on M3 Pro MacBook Pro

[aflynt]

I've recently upgraded my machine to an M3 Pro MacBook Pro, and I'm getting higher latency numbers that I would have thought using my UltraLite MK5. I tested this using the RTL Utility app. I'm consistently getting about 6.56ms latency at 48,000 Hz sample rate, 16 samples buffer size. For frame of reference, I'm getting about 1.125ms using my Presonus Quantum 2 on the same machine with the same settings. I do have the latest MOTU drivers installed. Is it possible that the drivers just aren't optimized for the new M3 chips?

-Aaron

[mikehalloran]

The only published spec from MOTU is 2.4 ms RTL@32/96 kHz with the Drivers installed. The difference between the MOTU driver and Core Audio is about the same as moving your ears about 14" closer to or further away from your monitor speakers.

The 16/48 RTL spec is not published but your measurement pushes those speakers about 18" further away.

[aflynt]

I'm getting 5.854ms RTL on the Ultralite MK5 @32/96k, which is over double the published spec. Just wondering if this is what I should expect out of this interface or if the drivers are just unoptimized for the new Apple M3 Pro chip. It seems quite a bit higher than it should be if the spec is accurate to real world. My Presonus Quantum 2 does just under 1ms RTL on the same machine @32/96k, which matches their published spec, but at half the sample rate and buffer size (64/192k).

-Aaron

[HCMarkus]

I'd initiate a MOTU.com TechLink and see what MOTU has to say about it.

[aflynt]

I contacted MOTU. It was a situation where the drivers appeared to be installed but weren't loading. I deleted the driver extension app, restarted, reinstalled and allowed the extension to run and. Now I'm getting 2.240ms RTL @32/96k, which is actually better than expected.

-Aaron

[mikehalloran]

I contacted MOTU. It was a situation where the drivers appeared to be installed but weren't loading. I deleted the driver extension app, restarted, reinstalled and allowed the extension to run and. Now I'm getting 2.240ms RTL @32/96k, which is actually better than expected.

-Aaron

MOTU was telling me today that there are occasional issues with drivers loading correctly over Apple Silicon and Ventura/Sonoma but they know how to get them resolved.. Good to see that you got it resolved.

There are Apple security issues that are not addressed in the MOTU documentation. I hope that they update it soon.