I learned how to enable it (it isn't enabled by default).
 
I created a new session and added a synth and guitar sound and began to play my guitar.
 
I loaded a heavy many voiced Galbanum sound into Rapture Pro in a 96k project.
 
I found I got crackles at about the same rate of play that I do before core balancing but now none of the cores approach a ceiling so I kinda lose my visual cue to back off.
 
I was really hopeful I'd be able to load huge patches and play lots of quick chords and have the old boy keep up...
 
I can say I was totally psyched to see the first core spread across the others.
 
In practice, it wasn't obvious to me that I gained much headroom before a crackle with Rapture Pro.
 
...
 
A long time ago, I made this video...
 
https://www.youtube.com/watch?v=0Bimx_qs7Jk
 
That shows some of the risk of crackling with many voiced sounds in Rapture Pro.

I found it very useful to read the core balancing documentation in order to understand when it can be of use. For example,  this in regard to you inserting a heavily laden rapture pro into the synth rack:
 
"Plug-in load balancing does not apply to the following:
Synths in the Synth Rack. These are not processed serially and do not benefit from this technology". 
 
Check out the full article here:
https://www.cakewalk.com/...p=NewFeatures.002.html

Exactly. Load balancing affects plugins in FX racks. We already load balance the synth rack by virtue of each synth being allocated to a worker thread. However depending on your project you may get a benefit from this even so since the FX rack load balancing could prevent one of the cores from spiking. To do more than that would require synths themselves to internally load balance their voice rendering which is a slippery slope.
 
Load balance is a major step towards solving common CPU load related issues but its not a solution to all bottleneck related problems. For example certain plugins could block processing under certain conditions. No amount of load balancing can solve a problem like that since its internal to the plugin. 
I'm curious what you see if you switch the CPU meter mode to show "System performance". Do you notice any spiking when playing your Rapture patch? What audio latency are you running at?

Noel, I'm grateful for you and all the folks at Cakewalk. Thank you.
 
System Performance
System Performance stays below what 2 or 3 bars mostly. Definitely below 5. So a tiny percentage of the available resource.
 
Latency
I tend not to go above 512 sample buffer which gives me a 24 millisecond round trip.
1024 predictably gives me a 48ms round trip, and at that level I can play chords without glitching for the most part, but I often hesitate from pushing the latency this high b/c it can confuse me when I hear the delays. It's like being on a VOIP phone call... lots of hesitate then rush.
 
Sonar isn't broken
Please don't take me wrong here. I'm not complaining that it SHOULD never glitch no matter the load that I throw at it. I just like to throw a heavy load when I'm noodling b/c I enjoy the sounds of Rapture Pro.
 
Playing with restraint is limiting
When I start to get into the groove... get rolling... I start to play harder... and suddenly, glitch glitch silence. Close and restart having lost all the recording. Most painfully, I lost the recording of a friend and I backing his teenage son (who was on keys) as he rapped for 1/2 an hour. 100% of the recording was lost when we got passionate and Sonar crashed due to Synth load.
 
Ways to work around constraint
It's been a risk for a long time, and I do it anyway. I know I can turn down the voices and I know I can pick lighter patches. I know I can switch a lighter patch to a heavier patch before bouncing it out.
 
I like to play it with my friends listening real time and I end up just taking my chances and watching that meter.
 
Really, I have it doing what I love. I should have read the documentation first and realized that it wouldn't solve this problem, but of course I didn't. I just jumped in, tested and posted.
 
Stopping the Synth
One thing that would be cool would be to have a better way to stop the synth from playing, so I'm going to describe the ways I try to do that. When I stop the synth I can play as hard as I want without fear of dropout.
 
Use Midi to Mute
I have a FCB Midi Foot controller I can use to Mute the incoming midi track. Then I can take off an play as hard as I want. The Roland GR-20 never glitches due to load, so I usually have a background drum, bass sound from the GR20 and TH3 Guitar sound at this point.
 
Use Midi to Fade then Mute
What I don't love about that fix is that tails from the synth get cut when I tap the mute button because it mutes both the synth output and the midi input. I really only want to mute the midi input and I tap the foot pedal. One way to get a blend is to fade the synth out with the expression pedal and then mute it. For some reason, faded to 0, the synth keeps working. I have to tap mute to avoid the chance of a dropout when I switch to chords.
 
So, this works ok but takes a little more thought.
 
Use Midi Event Filter
Something else I've done is use a midi event filter to block midi signal from the guitar from reaching the synth. This is my favorite, but I have never been able to turn it on and off with the FCB 1010. I usually just touch the screen to enable or disable this. Not perfect, b/c I have to take my hand off the guitar and it usually takes 2-3 touches to trigger it, but it also works ok and does not trim the tails.

I know it's not the same and stuff... but I tried yanking the plug on a batteryless laptop while recording with DigiCheck. Maybe I lost a few seconds at the plug yank... but the rest of the recording was saved.
 
It would be a nice feature to not lose the recording when Sonar fails to keep up with what's being thrown at the synth.

I just played for the last 30 minutes doing just what I described (never hit a mute button on Rapture).
 
But eventually the synths froze (rapture pro still playing a tone). SD stopped drumming and I had to kill Sonar because it wasn't responding.
 
And just now, as I type this, some piece of Windows Toast popped up saying Restart Required. Surely this was the cause.
 
I can't wait for the Linux version of Sonar. Have I read you're working on that? :P
 

Thanks for checking it out. To me your issue appears to be specific to Rapture. If you are glitching when there is low load then you should submit a bug report against rapture and mention which patch specifically causes this problem. Maybe there is a performance issue in Rapture itself that needs improvement.
 
>>One thing that would be cool would be to have a better way to stop the synth from playing
Im not sure I understand your reasoning here and why you need to stop the synth and what this has to do with performance load however.

Thanks, Noel. I've called support about Rapture load before. I've struggled to make videos of it glitching on me but they never come out. There's one above and you can hear it start to crackle.
 
There are a variety of patches that are an issue (usually the patches I like more -- Ambient crazy pads that create a blanket of sound beneath the guitar).
 
The reason I like to stop/mute the synth is because when I want to pick up the pace above the level the computer can handle, I need a way to reduce the load on the CPU. Muting the synth removes the constraint and allows me to play anything I want rather than dancing beneath the CPU speed limit. This usually coincides with me starting to sing some song rather than noodling over the pad.

I just did a quick test using a project that sure did hit the 1st core of my system before.
 
Now, with plugin balancing activated, my first core is NOT the highest anymore... most of the others are higher than the first, but are looking pretty well balanced IMO...
 
I cannot wait to try some CPU hogs this week-end to see (some heavy GUITAR RIG 5 presets that also used to cap my 1st core...)
 
Thanks bakers! I might still be able to postpone a new laptop purchase for another 2-3 years, thanks to this new core feature!

The new load balancing is absolutely wonderful... Thank u! I'm use to a robust desktop but have spent weeks with a new traveling laptop and all the recent improvements make this a pleasure. The load balance is the 'icing' on the cake!

Thanks all! Having so much fun these days!