CPU Spike at End of Song with 4 VI

[lowlights]

I have a session with 4 VI on it (and no audio tracks).

STRUCTURE with 2 MIDI tracks running to it (2 cello patches)

Two substantiations of MINI-GRAND (each with its MIDI track)

And SUPERIOR DRUMMER 2.3 (no separate MIDI, just an instrument track recorded to)

Some plug-ins, but not much - Channel Strip, a bit of compression, and the Devil-Loc Deluxe from SoundToys.

My whole session on the CPU System usage is about 27% on my i7 Win7 machine, 3 cores at 90% on a quad-core, 512 samples which should be plenty for mixing this. I'm running PT 10.1.2

Until the end of the song - when the CPU seems to randomly spike up into the red at 98%, the sound jitters and PT nearly crashes. This happens in playback and during a bounce.

I can't figure out what's causing this - although I did notice in one of the substantiations of MINI GRAND that the "meter" will start to peak higher and higher and then stay in the orange (not clipping into red), and stay there for 15-29 seconds, before releasing again and following the actual velocity of the notes playing (and then doing the whole thing again). So that doesn't seem right.

Anyone seen this? Is a note stuck on (I can't find any MIDI data that is out of whack). I know PT isn't the hottest VI DAW around, but why the spike? Is it the fact both MINI-GRAND are possibly grabbing for the same sample directory? Thoughts? Help?

Listening back to my bounce - I hear some light but gritty distortion in one of the MINI GRAND parts.

[Vincent Joly]

Hi,

Record your instrument tracks one by one in audio tracks and inactive your instrument tracks.

Vincent

[TimothyJohn]

Originally Posted by lowlights

I have a session with 4 VI on it (and no audio tracks).

Just for fun, I tried to set up a template session, where I could quickly switch between various VI's on the fly, using the track selector buttons on my Axiom Pro. (I'm using a 17" Macbook Pro 2.3 GHz quad i7 8gb ram OSX 10.6.8, Mbox 3, recording to a Glyph Portagig 500gb ext. drive, Pro Tools 10.1.3).

Having a blast!! Velvet, DB33, MiniGrand, Structure (one midi track with Concerto2 from Pro-Tools Expert), Xpand2, Hybrid, Vacuum, DrumCore3, and Strike. No midi recorded, no audio tracks, just a quick easy template to pull up and have at it with the various performance keys at my disposal--and of course a choice of drum tracks. Oh, and all bussed to one UA reverb powered by a Solo/Laptop.

But then---I instantiated my Ivory II Italian Grand to cycle between now three pianos (the Italian Grand is absolutely phenomenal), and the system crashes.
Not enough memory to install.

To fix, I have to go to an auto backup session and trash the one with Italian Grand. If I then delete the Strike track, I can install Ivory, but after that Strike will not install without crashing Pro Tools.

By the way, my buffer is at 128, and I've tried 3, 4, and 7 processors at 99%, and 8 processors at 85%. No go.

So, have I reached the limit of VI's I can install? Pro Tools claims 64 instrument tracks--I can't get past 9. But at 9, the session is slow to load. When it works though, it is very cool, just hit a track selector button on the Axion Pro and instantly cycle through the various instruments at will.

Is there anything I'm missing, or am I not being realistic by expecting more than 5 or 6 VI's open at once?

Thanks everyone!
Tim

[Vincent Joly]

I tried too with 19 instrument tracks (all arturia's VI, all PTIE and others) just to see. PT crashes very quickly.
Yesterday, in a session (13 mn) with Structure (2 patches), DB33 and Kontakt (2 guitars about 1,2Go samples), all ran fine.
My setup : buffer 512, 4 processeurs on 8, 85%.
Just wait for PT 64bit no ram limit.

Vincent

[TimothyJohn]

Originally Posted by Vincent Joly

Just wait for PT 64bit no ram limit.

Vincent

So, this is a ram issue? If it is, how does Avid make the claim that Pro Tools 10 will run 64 instrument tracks? Even on an HDX system, Pro Tools 32bit only supports 4gb max (and Avid claims 128 instrument tracks for Pro Tools 10HD). I'm assuming that under real use, a Pro Tools HD system would also top out at 5-10 VI's max---assuming this is ram.

If I'm missing something, please enllghten. That's too much discrepancy between 64 and 9. It sure would be nice to set up a template with all my VI's enabled on instrument tracks. Much easier to free associate and experiment within the DAW.

If it is a ram issue on the other hand, I think it is somewhat misleading for Avid to make a claim that Pro Tools 10 will run 64 instrument tracks. Unless they made the point that no VI's can be loaded on them.

I know it's tempting when advertising a product, to emphasize the highest potential specs under the most ideal circumstances. However in terms of customer loyalty and positive reputation, especially through word of mouth, Avid imho should post real world specs. For example, go to Glyph's website. They give real world track count specs of their drives on various Mac configurations. Very helpful.

Tim

[lowlights]

As suggested - I bounced each of my VI tracks to a stereo audio file.

The problem appears to be Superior Drummer (MIDI came from my Roland TD-4KX2). In the spaces in which the drums were NOT playing - and no MIDI data should be sending - I'd see the sudden creep on m CPU. If the drums came back in quickly enough - the CPU would drop back down (from say 70% to 24% again). At the very END of the song, the drums cut out a good 35-40 seconds before the final fade. That is when it creeps up from 24% to 70% to 99% and boom - session ends. Even if I stop the session the moment the drum part ends - and the session is no longer running - the CPU would still creep and spike.

SD 2.3 seems to be cycling the CPU for some reason. I found some "foot control" data (I'm guessing a heavy foot on the hi-hat pedal)? but even deleting that didn't help - it still spikes the CPU. The Mini-Grand and Superior do NOT appear to have been the truoble. I gotta go bug Toontrack now. But if anyone else sees this - let me know.

And thanks for the help.

[TimothyJohn]

Originally Posted by lowlights

As suggested - I bounced each of my VI tracks to a stereo audio file.

This of course is the generally accepted workaround. Is it true that a 64bit Pro Tools 11 would solve this problem? Would we be free to open--at will--memory hungry VI's such as Ivory, Omnisphere, Superior Drummer, DrumCore3 etc? (Assuming of course that they port their stuff over to AAX).

Tim

[lowlights]

I will definitely remember this work-around for future VI use, though I tend to record more acoustic (guitar, mando, bass) than VI. I can see running audio "bounces" is obviously better for Pro Tools (until that magical 64-bit day arrives)

I still wish I understood that spike though - it's as if Superior Drummer (or some MIDI command) was "leaving the light on" even though it had left the building, causing a CPU cascade. A note off that wasn't getting sent (or oscillating until a CPU spike occurred).

Well - I've got my work-around for now. My last mix was just a keyboard on Velvet, Superior Drummer (using their built-in MIDI grooves), and about 9 acoustic tracks. Topped out at around 19% on mixdown after plugins.

[lowlights]

With deeper digging, I found the answer here in the DUC. The problem wasn't the VI.

It was DVerb on that track - denormalizing and causing a CPU spike during the silent portions of the drum track.

Putting the Dither plugin before Dverb made the problem disappear. Now - mixing at 128 samples, all 4 VI never hit about 25% on my CPU. At 1024 samples, all 4 VI never hit about 13-14%.

DVerb, it seems, was the culprit. I just went over to the Toontrack forum and apologized for pointing a finger at SD 2.3!