Topic: Latencies on FireWire UFX aren't as low as I had expected

Hi again Guys,

I'm just in the initial phases of using my UFX with Logic Pro 9, on a Mac Pro 2009 Quad Core.  I was expecting latencies that were somewhere along the lines of 3ms for 32 samples but am not getting anything as low as that.

The latencies I am getting are:

Using FireWire:
32 Samples: 4.8ms round trip (audio breaks up, can't use this buffer)
64 Samples: 6.3ms round trip
128 Samples: 9.2ms round trip

Using USB:
32 Samples: 4.0ms round trip (audio breaks up, can't use this buffer)
64 Samples: 5.4ms round trip
128 Samples: 8.3ms round trip

My old Yamaha n12, which I had expected would not be as good as the RME given RME's reputation for amazing drivers, was delivering 3.3ms at 32 samples, and 4.7ms at 64 samples.

I have installed the current drivers for both USB and FireWire. I was expecting that the USB would in particular deliver really amazingly low latencies given the info on the website.

Does anyone have any advice? Is this in fact the latency I should expect? Or are there any tweaks I can try to get a better performance out of the UFX?

Cheers and thanks,
Mike

Re: Latencies on FireWire UFX aren't as low as I had expected

Hello,

I have a UFX and a Digi002 rack here, and Logic 9.1.3 (using a macbook pro C2D 2,4GHz/OSX.6.4).

I have the same latency with UFX as you. And I admit I have less latency with the digi 002 rack also (2,9ms@32, 2,9ms@64, 5,8ms@128).

Though, I don't find it is any kind of issue with Logic as far as you can desactivate the software monitoring (untick option in the audio preferences) and use Totalmix FX to monitor you recording tracks with zero latency.

But it's not normal that you cannot use 32 samples buffer size @44,1kHz. Here, I can record without any issue (but of course not with a big session), and my mac is far less powerfull than yours.

So
1/ Are you using a dedicated Hard drive (internal or FW @7200rpm) for audio and project files ?
2/ what is your OS version ?
3/ did you update logic to 9.1.3 (there is some fix for multi-core CPU) ?

RME UFX - TM FX 1.05 / Drivers USB 2.03 fw 1.58
Mac OSX.8.5 / Pro Tools 10.3.10+11.3.1 / VEP 5.3.1

Re: Latencies on FireWire UFX aren't as low as I had expected

Mike,

What are you using to measure the RTL (round-trip-latency) figures you posted above?  I'm assuming these are @ 44.1KHz.

The fact that you can't use the lowest buffer could be a system problem, but it is too early to tell unless other UFX owners chim in.

By the way, Demonic, your latency figures are only the reported ONE-trip buffer size and NOT the entire RTL figure as reported by Mike.  Just so you know, they're only half the story :-)


Take care!

Core i7 4770K | 32GB of RAM | Windows 7 Pro (SP1) 64 bit | Cubase 8.5 64 bit | RME FireFace UCX |

4 (edited by demozic 2010-11-17 18:23:39)

Re: Latencies on FireWire UFX aren't as low as I had expected

@JC28 :

I gave roundtrip latency measures (@44,1kHz), given by Logic, just like yeloop did.

@44,1kHz
Digi002rack :
0,7 ms (one trip) /1,5 ms (roundtrip) @ 32
1,5 ms (one trip) /2,9 ms (roundtrip) @ 64
2,9 ms (one trip) /5,8 ms (roundtrip) @ 128
5,8 ms (one trip) /11,6 ms (roundtrip) @ 256

UFX Firewire :
3 ms (one trip) / 4,8 ms (roundtrip) @ 32
3,7 ms (one trip) / 6,3 ms (roundtrip) @ 64
5,2 ms (one trip) / 9,2 ms (roundtrip) @ 128
8,1 ms (one trip) / 15 ms (roundtrip) @ 256

UFX USB :
2,2 ms (one trip) / 4 ms (roundtrip) @ 32
2,9 ms (one trip) / 5,4 ms (roundtrip) @ 64
4,4 ms (one trip) / 8,3 ms (roundtrip) @ 128
7,3 ms (one trip) / 14,1 ms (roundtrip) @ 256

Built-in audio in/out :
1,9 ms (one trip) / 3,4 ms (roundtrip) @ 32
2,6 ms (one trip) / 4,9 ms (roundtrip) @ 64
4 ms (one trip) / 7,8 ms (roundtrip) @ 128
6,9 ms (one trip) / 13,6 ms (roundtrip) @ 256

(NB : have the same results under OSX.5.8 and OSX.6.4)

Maybe Logic's measures are wrong (even built-in audio has less latency than UFX USB, only my mbox2 micro gets more)... ?

EDIT : I made a mistake on 32 samples buffer measurement on Digi002rack
EDIT 2 : another mistake in numbers (copy/paste error)

RME UFX - TM FX 1.05 / Drivers USB 2.03 fw 1.58
Mac OSX.8.5 / Pro Tools 10.3.10+11.3.1 / VEP 5.3.1

Re: Latencies on FireWire UFX aren't as low as I had expected

Have you measured the roundtrip latency with a loopback (output to input) connection and aligned the source and the recorded tracks in Logic to see the real world roundtrip latency including all hidden safety buffers and the latency introduced by the AD/DA converters or do you compare the latency given from Logics driver readout?

best regards
Knut

Re: Latencies on FireWire UFX aren't as low as I had expected

Also, the "I/O safety buffer" setting in Logic should be disabled for all measurements.
http://www.logic-users-group.com/index. … uffer.html

Regards,
Jeff Petersen
Synthax Inc.

Re: Latencies on FireWire UFX aren't as low as I had expected

@Admin Knut :

I compared latency given by Logic readouts. I didn't perform real world test. I'll do it as soon as possible because I have some doubt about Logic's measure reliability

To my ears, with software monitoring on and Totalmix monitoring disabled, with the same sample rate and buffer size, I have more "slapback" effect with 002rack than with UFX when recording my own voice. Regarding the numbers, should be the opposite.

@Jeff :

I am a Logic beginner not expert at all. So thanks for this info. Meanwhile, I cannot find this option in Logic 9 and the article seem to be Logic 8 related. I compared differents soundcards with the same settings so whatever IO safety buffer is engaged or not, we can "see" the differences.

But I will double check about this option before performing any "real world" measures.

RME UFX - TM FX 1.05 / Drivers USB 2.03 fw 1.58
Mac OSX.8.5 / Pro Tools 10.3.10+11.3.1 / VEP 5.3.1

Re: Latencies on FireWire UFX aren't as low as I had expected

Demozic,

Again, those latencies numbers you have posted for the Digi002rack are one trip only and don't even include the safety buffers nor AD figures (as the others have said).  Just your AD/DA rountrip is somewhere around 1.5 to 2ms, so getting RTL numbers that rival that is impossible.  That's how I knew they were wrong :-)  On the other hand, the figures you posted for the UFX sound about right as they're consistent with what I get on my FF400.  The rest is inaccurate.

Take care!

Core i7 4770K | 32GB of RAM | Windows 7 Pro (SP1) 64 bit | Cubase 8.5 64 bit | RME FireFace UCX |

Re: Latencies on FireWire UFX aren't as low as I had expected

Just your AD/DA rountrip is somewhere around 1.5 to 2ms, so getting RTL numbers that rival that is impossible.  That's how I knew they were wrong

Yes I agree, values about Digi002 rack and built-in ins/outs are weird and difficult to trust.

Again, those latencies numbers you have posted for the Digi002rack are one trip only and don't even include the safety buffers nor AD figures (as the others have said).

That's wrong. I would prefer saying that those latencies numbers are simply wrong and unrealistic. But that isn't one trip latency either ;-).

Once again I only gave what Logic displayed in audio prefs, and Logic gives 2 values, the ones I posted.

BTW, I tried making measures but it is not as simple as you think. Why? Because Logic (and also PT9) automatically compensate for the buffer in/out value (and yes, Automatic delay compensation is disabled). Whatever buffer size chosen, source and recorded track are already phase aligned.

So I have to record both source and "roundtrip" track at the same time and need to do this for each buffer size, fore each audio interface, with and without software monitoring  (or Low Latency Monitoring) engaged and with PT9 and Logic 9 in order to be sure what I am exactly measuring (and to be sure that no additionnal latency is introduced somewhere in the audio chain).

I will post results when I sort all of this out.

Thanks.

RME UFX - TM FX 1.05 / Drivers USB 2.03 fw 1.58
Mac OSX.8.5 / Pro Tools 10.3.10+11.3.1 / VEP 5.3.1

Re: Latencies on FireWire UFX aren't as low as I had expected

I just measured the Latency of the UFX in standalone mode, only Totalmix was running on the PC.

Methodology: a 200?sec wide positive impulse at a repetition rate of 100Hz appplied to an analog input of the UFX. Then routed through Totalmix back to an analog output. The input impulses were monitored parallel to UFX input with channels 1+2 of an 4 channel 100Mhz oscilloscope while the output of the UFX went to channels 3+4 of the ocsilloscope. So the delay between in and out was measured.
I measured: 1.26msec@44,1kHz, 540?sec@96Khz and 261?sec@192kHz.

11 (edited by demozic 2010-11-19 11:07:32)

Re: Latencies on FireWire UFX aren't as low as I had expected

Ok. After real life measure :

- UFX USB and FW gives me the same values above if, in Totalmix, I route the software output to hardware output and software monitoring is enabled in Logic9 (didn't find any IO safety buffer option but I have a french version).

If I disable Software Monitoring, and directly route input to hardware out with Totalmix, latency is fixed whatever buffer size used and give me 56 samples@44,1k  (1,27 ms), 51 samples@96k (0,53ms) and 45 samples@192k (0,23ms), which is close to Gerhard oscilloscope measures.

I made the same measure with PT9 and have same results (except @32 samples which is unfortunately not available).

- With Digi002R, the story is different :

With Logic9 / PT9 (LLM Off) / PT9 (LLM On) @ 44,1k
304 (240+64) samples (6,9ms) / 272 (240+32) samples (6,2ms) / 88 samples (2ms) @32
466 (338+128) samples (10,6ms) / 402 (338+64) samples (9,1ms) / 88 samples (2ms) @64
735 (479+256) samples (16,7ms) / 604 (476+128) samples (13,7ms) / 88 samples (2ms) @128
1376 (864+512) samples (31,2ms) / 1120 (864+256) samples (25,4ms) / 88 samples (2ms) @256

Conclusion : numbers given by Logic are pure fantasy and cannot be trusted depending on the interface used.

RME UFX - TM FX 1.05 / Drivers USB 2.03 fw 1.58
Mac OSX.8.5 / Pro Tools 10.3.10+11.3.1 / VEP 5.3.1

Re: Latencies on FireWire UFX aren't as low as I had expected

Conclusion : numbers given by Logic are pure fantasy and cannot be trusted depending on the interface used.

Thank you for the test. I think it shows, that the UFX delivers an excellent low latency performance. I don?t think Logic is to blame for the wrong latencies, as it depends on the numbers, given by the audio driver. But they are often not correct, so the numbers indeed cannot be trusted.

best regards
Knut

Re: Latencies on FireWire UFX aren't as low as I had expected

Admin Knut wrote:

Have you measured the roundtrip latency with a loopback (output to input) connection and aligned the source and the recorded tracks in Logic to see the real world roundtrip latency including all hidden safety buffers and the latency introduced by the AD/DA converters or do you compare the latency given from Logics driver readout?

best regards
Knut

Measuring the roundtrip this way will in my experience always result in lower than 'real life' latency. A signal sent to the output and back to the input - if that's what you mean by (output to input) doesn't travel through the same latency inducing steps that a recording situation in Software Monitoring mode does.

Re: Latencies on FireWire UFX aren't as low as I had expected

Sorry Latency, but you got that all wrong. Do a loop-back test and you get the latency of your device. Do it with plugins in between and you get the additional latency of your plugins.

15

Re: Latencies on FireWire UFX aren't as low as I had expected

IMHO Logic is to blame, as it is aware of all the buffers used and could calculate and display the real/total buffer size = latency easily. This way you would no longer see stupid values designed to fool the costumer.

I wonder if Logic is not using this 'total' size internally anyway? Otherwise a 002 (and many others) would not be able to record its own playback correctly, as the second track in Logic would immediately reveal a time offset (first track: playback, second track: record).

Regards
Matthias Carstens
RME

Re: Latencies on FireWire UFX aren't as low as I had expected

MC wrote:

IMHO Logic is to blame, as it is aware of all the buffers used and could calculate and display the real/total buffer size = latency easily. This way you would no longer see stupid values designed to fool the costumer.

That's exactly how SONAR does it, by reporting the real RTL values instead of those weird readings.  This has been double-checked with CEntrance, BTW. 

Maybe Apple wants to fool their users into thinking they get better latencies with Logic? :-P

Core i7 4770K | 32GB of RAM | Windows 7 Pro (SP1) 64 bit | Cubase 8.5 64 bit | RME FireFace UCX |

Re: Latencies on FireWire UFX aren't as low as I had expected

Install "AU Lab" with the XCode developer tools on your OS X disc. This allows to see all numbers if the driver reports them correctly. Look into the manual to get the AD/DA latency numbers if you want to know the exact driver buffer size.

Re: Latencies on FireWire UFX aren't as low as I had expected

Hi,

Been there doing that, thanks Timur cool

regards S-EH