2012 Mac Mini, 32 and 64 buffers, HDN Latency

[propower]

Hey all!

I am seriously looking at moving from a Metric Halo ULN8 to an AVID HDN Thunderbolt system. The main reason is for minimizing latency when tracking with VI's and Plug ins. I mostly do 16 track or less Singer songwriter, Jazz and other acoustic music (though drum VI's get used a bunch).

I currently have PT10HD, ULN8, 2012 Mac Mini (16G ram, two samsung 830 SSD's, 2.7GHz, i7, OS 10.8.4, 6 processors 99%). Even with a very stripped down session (one verb, a Waves Delay and Waves Comp), I still can not reliably run at 32 buffers (44.1 - 24bit). At 64 things are better but although the average usage is less than 15% there are spikes).

SO the questions ---
1) 2012 Minis - what is the lowest buffer you can reliably run and which interface are you using - is my problem more that my computer is the limit or is maybe the AVID integration with AVID hardware the real issue

2) If it is just the computer - is a faster proc or more cores -- (as in 2012 imac or Hex/12Core MacPro) the real answer...

Thanks much!
-Lee

[nst7]

As mentioned in your post on Gearslutz, you'll need to figure out what's wrong in your current setup that's making it underperform. HD Native won't make hardly any difference in this area. Whatever you use, you should be able to do a lot more than what you're doing.

Perhaps you could uninstall and reinstall eveything, making sure you have the latest versions of everything.

[propower]

I appreciate you responding in both places.

1) The install I am working with is only a few months old (been at the PT thing for 15 years).
2) I rechecked the entire optimization list - all is as it should be
3) I stripped all non AAX plugs out of the session - then took all plugs out of the session. - though usage went down - WRT to running at 32 samples no difference - very low usage on the meter (less than 10%) but fairly regular little spikes. 32 sometimes plays all the way through but mostly not.
4) All plugs at current rev
5) at 64 things are better - from 128 and up all is fine

Of course I can wipe the drive and reinstall everything - but we all know this is going to take some time etc... I can run from a clone and reinstall there but that brings usb3 into it.

Before I undertake that I would very much like to hear that others using the 2012 i7 mini in particular are able to run at these low buffers with AVID or other interfaces. From your input I don't see that you are using or have used PT10 with this machine at these settings. If you have I would very much like to hear your results.

PS>>> Something that does seem to sure these spikes for me and so far lets 32 samples go fine is checking the "ignore errors during playback and Record". When I tested latency yesterday I did find that checking this box actually increase latency a little (did not matter about checking the minimize I/O latency box). I usually never mess with this box but it does "fix" the issue so far.

[nst7]

I have not used that particular computer. Hopefully others who have will respond on here.

But as mentioned, I was able to do much more than that on my 2007 Dual Core Imac with Protools 7, 8, and HD9, running with a 003 and couple of USB interfaces here and there.

Now I have HD Native with HD10 on a 2010 2.8 Quad Core Mac Pro, which is still pretty modest for a Mac Pro. In fact I think your Mac Mini Geekbench score is significantly ahead of this Mac Pro. Not that Geekbench is everything, but it gives you some idea. I know that people with older Mac Pros who have switched to recent Mac Minis are very impressed with the performance upgrade, so these little machines are very capable.


So I'm hoping you will be able to sort this out. I would suggest perhaps starting with using another interface besides your ULN that was in your signature. Perhaps even uninstall the ULN driver. If you can't borrow someone else's interface, maybe just try your Mac's built in input and output.

I know Metric Halo is a great company, and there may be no problem with it, but it's just a place to start, basically to see if the issue repeats itself with other interfaces. I have seen instances of people using an interface and having trouble with buffers lower than a certain amount, even though with other interfaces it was fine.

Hopefully someone who is running HD Native on that computer will chime in.

[propower]

Thanks again for your reply... there is much here that is on point

- Regardless of my reluctance - creating an install of just the ULN8 drivers OSX and PT (no 3rd party plugs) is probably what at some point I will have to try.

- I don't have an alternate interface to try but like you said I could do the mac built in as an experiment.

- Just to be sure ... from your reply you do routinely run 32 sample buffer with out issues on smaller sessions with you MP and HDN PCIe (I assume)? No little spikes in CPU usage? No 6101's?

Thanks,
-Lee

[nst7]

On the Imac and 003 I mainly used 64 because it was perfectly fine and I could hardly tell the difference between it and 32. But I could run quite a few tracks with a bunch of plugins before I'd get errors.

On the Mac Pro, just a few days ago I did an experiment. On the Protools Expert website, they were promoting the Protools PC they've been discussing. They had a screenshot and caption where they were recording 128 tracks at 32 bit 96k, buffer at 32. CPU meter was at 21%. This was a new quad core I7.

I did the same experiment at the same settings. My CPU was at 32%. I let it go 3 1/2 minutes, which is a whole song length. It ran perfectly.

But, this was with no plugins.


If you can tell me what your session setup is, I can try to duplicate it, if I have the same plugins.

[quantise]

I use a 2012 mac mini i7 with an apollo with thunderbolt option installed.

You might find this video from the pro tools expert site illuminating:
http://www.youtube.com/watch?v=L-7ni7AybS0

After I saw this, I tried the same test on my own system but initially got disappointing results. Here's why.

I discovered that the firewire drive I was using, which had been delivered to me from a client with a session on it had been formatted in an MS-DOS format. This was already contributing to a flaky PT experience. On a mac when using a firewire drive, it must be formatted using the Mac OS Extended (journalled) option.

I then stripped out all plugins from all tracks except a comfort reverb on an aux track. Plugins of any type add additional strain to the system unless they are UAD plugs. Using Apollo you can record the UA plugins on input so a touch of DBX-160 is often part of my tracking workflow but it doesn't stress the computer.

I was then able to record up to 16-tracks simultaneously (my simul input limit) with a 32 sample buffer reliably. I can also drop in/out on all 16-tracks at 32 s/buffer cleanly using quick punch.

For initial tracking, you can use the Apollo's mixer app at 1024 s/buffer if you wish for a 'zero' latency experience but for tape style overdubs using auto input mode in PT, I find it more natural to use the lower sample buffer and monitor through Pro Tools. Using the Apollo mixer app in this context is like using input monitor mode in PT. In other words you always hear the input. If, however you need to do a quick overdub in the midst of a plugin heavy mix then the Apollo mixer can be a life saver.

So yes, 32 s/buffer using a third party interface is possible and I do it using Apollo with the thunderbolt card option.

Hope this helps.

John

[nst7]

The Apollo is handy for that, but he should not need any kind of external help to do something as basic as 16 tracks with a few plugins with a recent Mac Mini. That's pretty easy for most computers.

However, if he is not recording to an external drive, that could be the culprit right there.

[propower]

Thanks for the responses...

1) I use the internal Apple SSD for system and have an external Samsung 840 500G SSD in a Silver River 5G (USB3 super speed) case for audio. My testing on the rig when I got it showed R/W speed for the external of 450/350 MB/s.

2) THe "zero latency" monitoring with UAD effects features of the Apollo is of course great. In that area the ULN8 is also top notch and comes with a pretty big suite of things. Monitoring through the ULN8 hardware works perfectly and lets ProTools be at whatever buffer one needs. I am definitely addicted to how right this kind of monitoring sounds (published spec is 1.7ms at 44.1).

3) I did a CLEAN OSX, PT10.3.5 and Metric HAlo install on an external Samsung 830 256G drive in another USB3 case (exactly like above) - nothing else loaded! I ran the system with no plug ins and also with just a few AVID AAX ones -- all testing at 44.1 - 24bit.
-In both cases buffer = 32 was just barely stable (10 tracks total with audio on only 5) and playback would stop - 6101 error. 64 was better and in the 20 or so plays I did it kept going. Both of these still have the little spikes on the CPU graph with the spikes at 32 much higher.
- Again - checking the box that says "Ignore Playback and Record errors" totally fixes this. In the short testing I did there was never a click or pop.

4) I did a bunch of latency testing (using function generator and oscilloscope) for input to output total delay. I also tested this by singing a vocal and switching between MetricHalo monitoring and going through protools.
-At buffer=32 I got 5.6ms and going back and forth I could still hear the tonal shift between direct monitoring and going through PT. This of course gets worse as one backs off the mic and there is more live sound in ones head. If the HP are loud enough this is a dealable setting.
- At buffer = 64 and 128 I got 7.04ms and 9.9ms respectively. The sonic difference between these and direct monitoring are too much for me.

5) I definitely take notice that on the same computer - the Apollo system could drop in and out of 16 tracks at 32 buffer. On my completely stripped down system this would never fly. Is it possible that running from the external USB3 drive is it -- maybe -- If it was at all easy I would swap drives but I don't like messing inside a mini. And last time I imaged and rewrote my system drive I lost my fxpansion authorizations and they are a bit of a pain to get back.

Love to hear of a MINI - TB - Avid system low buffer report

Anyone in the Seattle area want to loan me a Omni and a TB box

[quantise]

Hi Propower,

Take a look at this Avid compatibility page:
http://duc.avid.com/showthread.php?t=54888

Under the compatibility sub heading where it talks about drives, you will read this:
"USB drives are not supported and are known to be problematic. Avoid using USB drives, as they are known for causing a variety of errors."

I'm inclined to think switching to an external firewire drive formatted appropriately will increase your performance with your current system.

I have to say, I also had issues when I tried to use a fast USB3 drive. Hopefully, PT11 may help in this regard when it comes.

Best,

John