Comparing UAD to RME latency with Logic X

Hi I have a question about optimizing latency in the UAD.
I have the latest black mac 12 core with Satellite OCTO and Apollo 8 (quad).
I'm running El Capitan with the latest version of Logic X 10.2.1

The Universal is amazing for live recording via the Console but I find my Fireface a bit better for playing midi instruments (I use tons of midi / Kontakt libraries for film composing)
For instance, when loading up a piano patch, the Fireface feels a bit crisper and the UAD a very very slight latency in the feel of the attack.

I'm considering going back in forth on both interfaces. But before committing to this plan was wondering if these UAD numbers look normal for my setup or if there is a way to get the UAD closer to the Fireface latency numbers? Thanks in advance!

Universal Audio Apollo
I/O Buffer Size 128
Resulting Latency 12.9 ms Roundtrip (3.4ms Output)

Fireface 800 (2EE)
I/O Buffer Size 128
Resulting Latency 9.7 ms Roundtrip (5.1ms Output)

Universal Audio Apollo
I/O Buffer Size 64
Resulting Latency 10.0 ms Roundtrip (1.9ms Output)

Fireface 800 (2EE)
I/O Buffer Size 64
Resulting Latency 6.8 ms Roundtrip (3.6ms Output)

The roundtrip latency figures you have for the Apollo seem a little high. I'm getting a roundtrip of 5.5ms and 8.4ms for 64 and 128 buffer sizes respectively (according to the settings window in LPX). Are you using thunderbolt to connect the Apollo?

When I had the Fireface I usually ran it at 64 and sometimes 32 with occasional glitches. It was a great unit. The Apollo is at 32 on Thunderbolt constantly. Never had a glitch.

n1kk666 said:

The roundtrip latency figures you have for the Apollo seem a little high. I'm getting a roundtrip of 5.5ms and 8.4ms for 64 and 128 buffer sizes respectively (according to the settings window in LPX). Are you using thunderbolt to connect the Apollo?

Click to expand...

Wow 5.5ms is awesome. Yes I'm running Thunderbolt. Everything is top notch. Not sure why I'm not getting your numbers.

Noticed something interesting. When I restart the computer fresh and open Logic, the latency says:

Universal Audio Apollo
I/O Buffer Size 64
Resulting Latency 3.3 ms Roundtrip (1.6ms Output)
WHICH IS GREAT!

BUT
When I close Logic and reopen it goes back to
I/O Buffer Size 64
Resulting Latency 10.0 ms Roundtrip (1.9ms Output)

Will do more testing...

A few things to consider:

-What connection, TB or FW?

-Is your satellite FW?

-What sample rate are you doing your testing at?

-Did you disengage the Apollo's Input Delay Compensation in the Console?

-The RTL latency will creep up with the Apollo every time you change the sample rate and come back. This seems to be a bug. A fresh reboot and no sample rate change with IDC off will yield the lowest numbers.

-Over TB1, I get 4.0 ms at 32-buffer 44.1kHz with console IDC off in logic and Reaper! (4.76 in studio one)

DanButsu said:

A few things to consider:

-What connection, TB or FW?

-Is your satellite FW?

-What sample rate are you doing your testing at?

-Did you disengage the Apollo's Input Delay Compensation in the Console?

-The RTL latency will creep up with the Apollo every time you change the sample rate. This seems like a bug. A fresh reboot and no sample rate change with IDC off will yield the lowest numbers.

-I get 4.0 ms at 32-buffer 44.1kHz with console IDC off in logic and Reaper! (4.76 in studio one)

Click to expand...

Thanks this info really helps. I was testing at 48k. My Satellite is Thunderbolt.
I disengaged the Input Delay Compensation and played around with the numbers after a fresh restart:

Universal Audio Apollo
I/O Buffer Size 64 (96Khz)
Resulting Latency 2.7 ms Roundtrip (1.0ms Output)

Universal Audio Apollo
I/O Buffer Size 64 (48Khz)
Resulting Latency 5.3 ms Roundtrip (1.9ms Output)

Universal Audio Apollo
I/O Buffer Size 64 (44.1Khz)
Resulting Latency 5.8 ms Roundtrip (2.1ms Output)

Universal Audio Apollo
I/O Buffer Size 32 (44.1Khz)
Resulting Latency 4.0 ms Roundtrip (1.2ms Output)

These numbers are pretty great, I guess this solves the issue. It's good to know I'm getting the same numbers you have. Will have to put this setup through a real world test soon but so far so good!

Glad I could help. I went through the same thing a while back and was confused with the numbers at first too. Matt H has done some extensive tests as well and will post his findings soon once he can retest.

Let us know how it performs for you. Cheers, Dan