DP - iMac 5K - ULN8 3D issue

[BERLY]

Hi iMac 5K users,

I recently purchased a new iMac 5K with 64 GB of RAM. This iMac is connected to 4 Metric Halo ULN-8 3D in Ethernet.

When I record 24 or 32 tracks in DP via the ULN-8, I cannot work at sample rates higher than 44.1KHz, if not, after a few minutes of recording, DP stops and I have the following messages:
«Audio playback has overloaded your computer's processor… etc»
And a few seconds later :
«DP is not receiving a clock signal from the audio hardware∞ etc»

• Without DP, with just my ULN-8s and the MIO interface, I can record 32 audio tracks for hours at 192 KHz without any hassle.
• With DigitalPerformer disconnected from the ULN-8 3D, I can play dozens of audio tracks up to 192KHz without any worries.
• As soon as I plug the Metric Halo driver into DP, I can no longer work at high frequencies.
• With my four ULN8 connected to my old MacBookPro, much less powerful than my iMac, I can record in dp at 192KHz without any problem

- All my software and drivers are up to date (compared to Mojave)
- My tests were carried out with zero plugins
- I have the same result by disconnecting EVERYTHING connected to the iMac except the ethernet cable from my ULN-8s.
- I tried changing the few possible settings of DP (priority, buffers size), but it doesn't change anything.
- According to the Apple Activity Monitor, I am only about 10% CPU usage.
- PowerNap is not active nor energy savers (suspension of disk activity etc).
- My screen setting is Adobe RGB

Metric Halo and MOTU technical support are not giving me a satisfactory answer for the moment.

The only thing MOTU told me about a graphics display latency of DP is that DP 10 was not written "with the thought" of 5K. I have no idea or skill for know if it can be related or not. According to MOTU Tech, the answer is no… I don't know how to know if it is related to CPU, GPU or something else…

Are there other people who would have the same kind of station as mine here?

Do you think the iMac may have a problem (faulty memory card or something ...)? Any other idea or suggestion?

Thank you for your help
Regards,
Christophe

[mikehalloran]

As soon as I plug the Metric Halo driver into DP, I can no longer work at high frequencies.

Ok… What do you see in Audio MIDI Setup.app (in your Utilities folder) when your interface is on? It should show up in the list on the left and you should be able to set your default to 192000 there.

What do you mean by a "new iMac 5K"? All 27" iMacs since 2013 have 5K screens.

I have a 2020 iMac and a new, iMac Pro (2017 model). There's no difference in the audio processing between the two. Likewise, both have the T2 chip.

A couple more thoughts… Have you properly added the Metric Halo drivers to Security? You have about 30 minutes installation to do this. If in doubt, reinstall the drivers and check. This article applies to nearly all apps and drivers these days—it's not MOTU or High Sierra specific.
https://motu.com/techsupport/technotes/ ... igh-sierra

Has Metric Halo or DP asked for access to any folders or the microphone? If so, grant access — no need to do so for Contacts.

[leigh]

I have a ULN-8 and would suggest you be sure your ethernet cable is Cat6, and swap it for another Cat6 cable if you haven't already.

**Leigh

[mikehalloran]

I have a ULN-8 and would suggest you be sure your ethernet cable is Cat6, and swap it for another Cat6 cable if you haven't already. Mike has some good suggestions, too. The security stuff is annoying.

**Leigh

Oooooh… good point!

If you have a 2020 iMac with the 10GBE option, a Cat6 cable or better is essential but if running at 192kHz as you state, Cat6a is better because it is quieter. You do not need Cat7.

https://community.fs.com/blog/should-we ... 250%20MHz.

[BERLY]

Thanks all,
A few answers below:

What do you mean by a "new iMac 5K"? All 27" iMacs since 2013 have 5K screens.

iMac (Retina 5K, 27 pouces, 2019) with a Radeon Pro Vega 48 8 Go

A couple more thoughts… Have you properly added the Metric Halo drivers to Security? You have about 30 minutes installation to do this. If in doubt, reinstall the drivers and check.

I cannot remember, but I suppose that yes. Otherwise I wouldn't have been able to work, isn't it? But I will try…

Has Metric Halo or DP asked for access to any folders or the microphone?

No. So I've just authorized both and I'll check if it changes anything.

I have a ULN-8 and would suggest you be sure your ethernet cable is Cat6, and swap it for another Cat6 cable if you haven't already.

If you have a 2020 iMac with the 10GBE option, a Cat6 cable or better is essential but if running at 192kHz as you state, Cat6a is better because it is quieter. You do not need Cat7.

I am using Category 5 cables provided by Metric Halo. So maybe this is the good answer, but on the other hand, I can use the same cables for my four ULN-8 connected to my MacBookPro without any issue, even at 192KHz. But maybe this is not the same ethernet protocol on the iMac? BTW, 96KHz is enough for me.

I'll check all of that as soon as possible, and purchase four Cat7 cables. Thank you very much.

What would be great is to find someone using a 5K 2019 iMac with DP and ULN-8 3D to be able to compare performances

Best regards,
Christophe

[mikehalloran]

You have a 2019 iMac. No T2 chip and nothing faster than Gigabyte Ethernet.

Cat5e is fine unless you have a long cable, say over 25 meter, then you want to step up to 6a because of the noise reduction.

If you did not add DP and the Metric Halo drivers under System Preferences/Security, then they weren't added. They don't get added by themselves in High Sierra or later. Reinstall both and add per the tech tip. Apple has docs that say the same thing but the MOTU doc is shorter.

[BERLY]

My cables are 5E MetricHalo cables. The first is a 3 meters and the 3 others are 0.40 meter cables.
I've reinstalled the MH drivers, but it changed anything.

I'd really like to know if other people than me are able to work with DP 10 + ULN-8 3D on an iMac 5K 2019 with high frequencies.

Thanks all
Best regards,
Christophe

[mikehalloran]

My cables are 5E MetricHalo cables. The first is a 3 meters and the 3 others are 0.40 meter cables.
I've reinstalled the MH drivers, but it changed anything.

I'd really like to know if other people than me are able to work with DP 10 + ULN-8 3D on an iMac 5K 2019 with high frequencies.

Thanks all
Best regards,
Christophe

What does Metric Halo support say?

[BERLY]

I'm speaking with Jon Stern from MH for month now. But nothing concrete comes out of our discussions unfortunately for the moment.
I've just wrote on MIO forum. I hope it will link me to people who would have a similar station with or without the same issues…

[BERLY]

Hi all,

After doing many tests, in collaboration with BJ Buchalter at Metric Halo, the solution may be found inside this video: https://www.youtube.com/watch?v=LC6CX4RtQFM&t=284s

So I’ve set the iMac 5K Manuel Ethernet Hardware setup to Standard 1500, not Jumbo 9000 any more. So far, it seems to work great after a few hours working at hight frequencies (96KHz 192KHz).

I hope this Ethernet setting does not cause other unexpected problems elsewhere. Any advised opinion on this subject?

I've also created an aggregated set in the Apple Audio Window. I don't know if it helped or not. I just know that aggregated setting with Ethernet settings on Jumbo 9000, it didn't worked for me.

I also hope that this information can help other professionals who are facing this bug, and so that they’ll not have to search six months before finding a workaround, which seems to be already known to MOTU technicians.

Best regards
Christophe

[mikehalloran]

Makes sense. I can't imagine that Apple supports Jumbo Frames over gigabit Ethernet. Glad you got it solved.

https://blue42.net/networking/4-things- ... bo-frames/

[Henry Robinett]

Let me know how this works. I’ve had similar problems with DP and my 5 ULN-8s even before I got my 2019 Mac Pro. I’ve done just about everything. No help from MOTU but BJ and guys at MH have been incredible. I went so far as replacing the cards in all the MH boxes and got rid of mixed ram, which was stupid. Eventually I moved away from DP. I have a lot of old projects in DP so I will always be coming back. In Logic and PT I haven’t had a crash but going back to DP it will crash standing still with me doing nothing. And I get that alert about overloading the processor. I think I did what BJ told you to do but I’ll check. He even went so far as to write a special driver for me that worked on earlier MH drivers. Then I bought it was my old MTP. So I replaced it. Not really a change.


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[BERLY]

Hi Henry
Good to meet you here. I remember you well and your many interventions on the MOTU list.
Me too, it often happened to me what you describe: Even while doing nothing, I had this alert, like you.
Since I put Manual Ethernet on 1500 Standard, no more problems, so far.
Like you, MOTU didn't help me much. On the contrary, it made me waste a lot of time with unnecessary chatter.
BJ is actually trying to find the loophole. They are true enthusiasts of MH.
Could you tell me one thing, please: When we have worked on DP for 25 years, what is the easiest software to learn? Logic or PT?
Does the transition take long to know and master all the small details of a workflow?
(Sorry for my summary english)
Thanks
Bes looks,
Christophe - www.studio-slc.com

[Henry Robinett]

Hello. There is some bug that is in DP that doesn’t like Ethernet or something in the way MH operates. I don’t have this with any other software. I was away from DP for months with no problems then bam. Crashing is back.

PT is definitely easier to adjust to from DP perspective. Logic just doesn’t make a lot of sense and is frustrating to me. That said I’ve been on Logic for several months. I guess I like to torture myself.


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