How to freeze *some* (not all) of the synths of a multi-out vsti synth engine (ARIA)

I currently have a problem: I am working with Sonar X1d Expanded on a symphonic piece using over 60 different instruments with their articulations, all Garritan sampled instruments played back on 4 instances of their ARIA player (a multi-out vsti plug-in). 


So each instance of the ARIA player is a 16-out synth capable of playing 16 different sampled instruments (tracks) in my score. On top each instrument uses a lot of different controller data to control attack, articulation and other parameters. As I am still running (SONAR and synths) on one machine (at the moment) I am starting to run out of juice and experience more and more drop-outs, even though I use almost no effects at this stage. 


To reduce the CPU load I tried to "freeze some MIDI tracks", i.e. freeze the synth outputs associated to these tracks.  For example if I want to freeze all the woodwinds to work on brass and one of the brass instruments resides in the same instance of ARIA as any of the woodwinds I want to freeze, it will get frozen as well ! It doesn't take long to get all ARIA instances frozen. 


I would assume that "freezing" a (MIDI) track would simply render it to an audio track (mono or stereo) and then mute the associated MIDI data to free-up the CPU. It is a very convenient and reversible way (one click) to simply bounce to audio, I don't plan to edit the audio for now, only later while mixing. 


Does this make any sense?  How would you attack this problem?  Grouping similar instruments (e.g. woodwinds) on the same ARIA instance would apparently help but sometimes you need to freeze in a different order. 


In essence: what is the difference between "freezing a MIDI track" and bouncing its audio to track? It seems that freezing applies globally to synths and not to individual tracks using these synths but why is it so?  It seems like such a useless limitation but I admittedly probably don't understand the technical difficulties associated with it.  Thanks for any help in elucidating this question! 

Yes Bob, you understood my problem perfectly and, sadly, have the same...
Let's hope for someone to give us an alternative way to do it OR for Sonar developers to add this capability. 

Or freeze everything and then just move the frozen tracks you want to a new audio track and adjust volume etc. on the new track.. Then you can unfreeze the synth and mute the tracks you moved to audio.

Lance

I have noticed this, too. There is a freeze track "widget" on every MIDI and Audio Track... but on a multi-out synth (such as EWQL Play - and others), freezing one MIDI or one audio track freezes the whole VST - not just the intended track. IMHO this is a BUG because the entire synth can be frozen from the synth rack view (other places, too?) and there'd be little reason for individual track freeze widgets which imply that using them should freeze their track ONLY. Thank goodness for the workarounds listed here and for real [multi-timbral] hardware synths! :)

IIRC the Bounce to tracks also leaves the pro channel functional whereas freezing does not.  I tend to equate the capturing of synth outputs with tracking of real world inputs e.g. vocals / guitars etc, so I prefer bouncing as it lets me break the workflow into tracking -> mixing -> mastering.  Freezing is handy if you want to offload the CPU while tracking to capture other instruments.

Cheers

Grif

Thanks to all for your insightful answers.  I finally grouped my instruments' MIDI and Instrument tracks by family (e.g. woodwinds) in separate folders and fast bounced each of them in turn to tracks (thanks Scott!).  It worked nicely but I still experienced audio dropouts.  I was really surprised so I tried to mix down to stereo, mute every other tracks, and strangely still experienced dropouts!!!

I then did a simple experiment: I just resized my Sonar window to one monitor (it was spread across four 2560x1600 screens before). No more dropouts... EVEN playing all 60+ tracks straight from the synths!!! That was a lesson:  video updating (even with fast cards and latest drivers) can really kill your audio!

Another lesson (and question):  each bounce merged (and actually killed) the original individual tracks.  Is there any way to prevent that?  Thanks!!!