Hardware Drive / Work Priority settings

[Tripi]

I'm about to hook up a new Apogee Ensemble interface in my studio, and took a quick read through the manual. They show an example of how to set DP's audio settings for the Ensemble, and it indicates that you should set the Work Priority to LOW. I've always had my setting on HIGH (for my old Motu 828 mkII). The manual doesn't go into much more detail, but does anyone know why Apogee would recommend this?

thanks!

[jloeb]

I don't know, but I can tell you that following that suggestion has given me a trouble-free experience with the Ensemble, so it's definitely worth doing.

[mhschmieder]

Magic Dave explained why a year or so ago. I don't have time to hunt down that post right now, but generally non-MOTU interfaces do better at Medium to Low Work Priority, and if one has problems it is usually best to lower the Work Priority vs. raise it.

A quick forum search does find two highly relevant posts, though:

http://www.motunation.com/forum/viewtop ... ty#p375212

http://www.motunation.com/forum/viewtop ... ty#p374004

These posts, in fact, specifically address the Apogee interfaces and also quote Magic Dave's recommendations and explanations. This is probably sufficient.

[Tripi]

Those are good reads... thanks. Sounds like a good rule of thumb is: High Priority for MOTU interfaces, and Low or Medium for non-Motu interfaces.

[Armageddon]

I followed Magic Dave's advice and actually got decent results on my machine. My Work Priority is set to "Medium", and after much experimentation, I discovered that a buffer setting of 1024 with a Host Multiplier of 2 (as opposed to a buffer setting of 2048 with a Host Multiplier of 1) allowed me to play and record MIDI from my VIs with almost zero latency at 44.1 kHz/16-bit, as well as let me freeze and bounce audio from them at 96 kHz/24-bit with virtually no difference in performance. If I'm using particularly taxing sample sets, like Symphobia, I have to nudge up my hardware settings to 2048 with a Host Multiplier of 2 when recording audio at 96 kHz/24-bit, but this is only good for audio, not playing or recording MIDI from VIs. I always try to keep my project's sample rate and bit depth low until it's time to convert to audio files, and the 1024/Host Multiplier 2 buffer combo seems plenty generous, even if I'm running multiple soft-synths and time-based effects in real time.

[daniel.sneed]

[...]My Work Priority is set to "Medium", and after much experimentation, I discovered that a buffer setting of 1024 with a Host Multiplier of 2 (as opposed to a buffer setting of 2048 with a Host Multiplier of 1) allowed me to play and record MIDI from my VIs with almost zero latency at 44.1 kHz/16-bit[...]

Wow! Seems really stunning to me, Armageddon. I'd like to be in the situation you describe, for better CPU handling. Are you talking about any rhythmic playing kind?
I generally set my own to 256, multiplier 1, to get perceived, but acceptable, latency with VIs. When it comes to percussive samples playing thru mallets on a Pad, I go down to 128. And I'm not *that* picky about timing.

[Armageddon]

I generally set my own to 256, multiplier 1, to get perceived, but acceptable, latency with VIs. When it comes to percussive samples playing thru mallets on a Pad, I go down to 128. And I'm not *that* picky about timing.

I'm talking about any playing -- drum kits, samples, real-time soft-synths. There's an eensy bit of lag if a lot of things are happening at once, but it seems to be as close to real-time as I've gotten. If I had my hardware buffer set down as low as you do, I'd probably choke on just a few tracks playing at once, even at 44.1 kHz/16-bit. Every once in a while, if I replace my DP prefs after a hard crash (rare since 7.2!), I forget that my buffers go back to default (512 with a Host Multiplier of 1) and large projects choke before I remember to reset them to my personal prefs.

Also, how are you set up on your machine? Do you have a lot of other apps running at the same time with DP, like Dashboard, the Internet, Norton Antivirus, Time Machine, Plogue Bidule, ReWire? What's your hard drive speed? How often are you defragging? I had to run through the gamut to get things running as smoothly as I have, and even so, my rig is pretty slow.

After following a similar thread on here, where we'd discussed how high you could comfortably set your parameters, I had assumed I could only go as high as 1024 with a Host Multiplier of 1, with everything else above that grayed-out -- I was shocked to discover I can go all the way up to 4096. A lot of that may have to do with my interface, also. TC's Konnekt series has several settings for its buffer usage inside of its TC NEAR console, with the recommended setting being "Safe Mode 3". It had defaulted to a much lower setting, and for a long while, I was ignorant of being able to adjust it at all. Once I got it set properly, I was able to access much higher buffer settings. The Host Multiplier trick is something I learned about back in my Vision DSP days: smaller but more numerous buffers is somehow more efficient than one large buffer equaling the same amount. However, like I said above, it's tricky, for me. Set it too low and the audio gets glitchy, set it too high and the VI latency can be off by half a second or more. I've been working on some pop-type material lately (disco, long story) with drum work as well as a keyboard solo, and I probably would have swallowed bleach if I'd had to slog through it with any sort of lag.

[Phil O]

Apogee uses Apple's FW drivers. A few OS's back, there was a problem with audio dropouts using Apogee firewire hardware and DP. The dropouts were very short (one or two samples) and would sound like an occasional click or static (if there were several in a row). The solution at the time was to do one of two things. Download a beta version of the next FW driver from the Apple Developer Site, or set DP's work priority to low. Apogee posted the low work priority setting solution in their FAQs and it has remained there ever since. I can't remember if they even identify it as a firewire specific problem.

I downloaded the FW driver and was able to keep my work priority at high. I forget which OS included the new driver, but that problem is no longer an issue. I've been using my Rosetta 800 with DP and OS 10.6 without a hitch and have my work priority set to high. I would suggest trying it on high and adjusting it lower only if you experience clicks.

Is the Ensemble firewire? Might not even be affected by this.

Phil

[daniel.sneed]

[..]Also, how are you set up on your machine? Do you have a lot of other apps running at the same time with DP, like Dashboard, the Internet, Norton Antivirus, Time Machine, Plogue Bidule, ReWire? What's your hard drive speed? How often are you defragging? I had to run through the gamut to get things running as smoothly as I have, and even so, my rig is pretty slow.

Well, I keep my system as clean as I can :
- fast HD : Seagate Momentus 500 Go, XT serie including a 4Go SSD memory, 7200 rpm. Heavily partitioned HD (9 partitions). All is done in this internal HD, including samples. External HDs are for backup only.
- defrag monthly with iDefrag
- OnyX maintenance scripts : daily, weekly, monthly
- memory 8Go (6Go could have been enough, I believe)
- tracking mostly at 44.1 / 16bits
- very few other apps running : Reason, Rewire, Automap, Activity Monitor, Time Machine. No Dashboard, no Plogue Bidule, no antivirus. Airport and internet off. Airport is On only while upgrading or authorizing. My MacBook usage is strictly music only.
- few VIs used, as you can see in my signature : mainly GPO Aria, Absynth, Reason, V-Station, Automat.
- very light on FX while tracking, at buffer 128 or 256. But rather high on FX while mixing, at buffer 1024.
- glancing, from time to time, to Menumeter free memory display, in menu-bar. Close and re-launch DP in case used memory comes close to 4Go.

[Armageddon]

Well, I keep my system as clean as I can :
- fast HD : Seagate Momentus 500 Go, XT serie including a 4Go SSD memory, 7200 rpm. Heavily partitioned HD (9 partitions). All is done in this internal HD, including samples. External HDs are for backup only.
- defrag monthly with iDefrag
- OnyX maintenance scripts : daily, weekly, monthly
- memory 8Go (6Go could have been enough, I believe)
- tracking mostly at 44.1 / 16bits
- very few other apps running : Reason, Rewire, Automap, Activity Monitor, Time Machine. No Dashboard, no Plogue Bidule, no antivirus. Airport and internet off. Airport is On only while upgrading or authorizing. My MacBook usage is strictly music only.
- few VIs used, as you can see in my signature : mainly GPO Aria, Absynth, Reason, V-Station, Automat.
- very light on FX while tracking, at buffer 128 or 256. But rather high on FX while mixing, at buffer 1024.
- glancing, from time to time, to Menumeter free memory display, in menu-bar. Close and re-launch DP in case used memory comes close to 4Go.

And you still aren't able to have higher buffers while tracking? I'm assuming Reason is being used via ReWire? I usually do my drum tracks via EZDrummer as a tone module VI, and my orchestral stuff, basses, guitars and other high-end samples are all usually via Kontakt 4 or PLAY, all in pre-gen mode. I run a plethora of soft-synths, like the Rob Papen synths, Minimonsta, ImpOSCar, KORG Legacy, FM8, B4 II, Massive, Pro-53, Jupiter 8V, ARP 2600V and CS-80V in real time. All of that, however, is inside of DP, no ReWire or Plogue Bidule. I also run an instance of EZDrummer with a 4/4 or 3/4 loop for timekeeping. I'm just trying to figure out why your computer, which is a 64-bit machine, faster and with four times as much RAM would need a lower buffer setting (unless it's assumed that a lower buffer setting is better?) to run VIs without latency.

[Dan Worley]

- tracking mostly at 44.1 / 16bits

16-bit?

Why, Daniel, Why?

Oh, the humanity!

c-ya,

Dan Worley

[HCMarkus]

- tracking mostly at 44.1 / 16bits

16-bit?

Why, Daniel, Why?

Oh, the humanity!

c-ya,

Dan Worley

+1

[donreynolds]

16 bit is audible difference from 24.

[Armageddon]

16-bit?

Why, Daniel, Why?

Oh, the humanity!

I do exactly the same thing -- on my machine, CPU and RAM are at a premium, so I record all my VI MIDI tracks at the lowest bit-depth and sample rate possible, which allows me to record and play back more tracks with a lot more versatility, and is pretty much essential on a movie score, when I'm also running an HD movie in real time synced to my audio. Why would you need a higher setting just to record MIDI? Once I've got my tracks finalized, I simply convert my project's sample rate and bit-depth to my desired format (usually, 88.2 or 96 kHz and 24-bit) and lay off the audio. It saves my processing til I need it. Granted, on a Mac Pro, or even a latter-day i5 or i7 machine, this may not even be a concern, but on a slower machine, when you're running 20 or so MIDI tracks of multi-layered Kontakt orchestral samples, real-time soft synths and an HD QT movie through your DVI port all at the same time, every little bit helps. Thanks in no small part to DP 7.22, things switch over with minimal fuss, so even us guys with older hardware can keep up (more or less).

[Dan Worley]

16-bit?

Why, Daniel, Why?

Oh, the humanity!

Why would you need a higher setting just to record MIDI?

You don't. I didn't know you guys were talking just about MIDI.

c-ya,

Dan Worley