Load Testing and Question about Performance Meter

Probably a good ideal to put your system spec in your signature, including operating system etc (see my sig).

If your machine is Intel consider turning off Speedstep at the BIOS level (there is an AMD equivalent). Optimize your Windows power settings as well by adjusting min/max core settings (this is what it's called in Windows 7 anyway, windows 8 it is different). You may need a reg hack for this (google for details).... you don't need to adjust the windows settings though if you turn off speedstep at  BIOS level.
 
Otherwise it could be any plugin slowing you down (you can rule it out by removing instances), or bad drivers/firmware or you need to do some latency optimization. Or maybe you need to optimize windows (chkdsk/defrag). There is a wealth of information in these forums about how to handle this. The question pops up every couple of weeks in this forum.
 
Cheers...

Yes I read your post. Please check #1 esp speedstep. I'm asking for system specs for my benefit so I can deal out more specific advice rather than having to waste time covering all bases. Time is apparently money or something :) You have the generic advice anyway posted in #1. Thanks and good luck..

Teal
The machine is exceeding my expectations, I'm just wondering why the meters are only showing about half before it starts to crackle. 

The CPU meters in Sonar show how quickly the buffers empty. Not the actual CPU usage. It is a more accurate way to predict performance within the DAW. However there is a switch in the audio ini file I believe that can improve core balancing. 
 
Below is a copied sectioned from a post from this thread. http://forum.cakewalk.com/Multicore-use-dedicate-first-core-for-only-OSDAW-m3000964.aspx  Post no. 5. It still applies I believe.
 
"9- Sonar Tweaks:
* Improved Multi-Core load balancing [From Noel's SONAR 8.3 Log]

Since all systems are not made equal we decided to make this new scheduling mode configurable.
From the help file, the new aud.ini option to control this is:

ThreadSchedulingModel=<0 - 2>
Type Integer
Default 1

This variable goes in the [Wave] section and controls the interaction of the main audio thread and worker threads on multiprocessor systems when the Use Multiprocessing Engine option is enabled. Depending on the system, a particular model may result in less glitching and better overall performance. The values are as follows:

............0 = Same as previous versions of SONAR.
............1 = (default) Better thread balance. Model is more efficient and can provide cycles for other tasks.
............2 = Additional worker thread is created. This may result in improvement with Quad processor systems or higher. Not recommended for Dual processor systems."

If you're getting dropouts with the CPU meter at 50% that suggests something in the system may be hogging a resource, and not necessarily the CPU.
 
Network and video adapters are frequent culprits, since they assume they're at the top of the food chain and tend to monopolize resources at the expense of audio. Try disabling your network and see how much difference that makes. In the case of wireless network adapters it can be night and day. The smoking gun is high DPC latency, which doesn't show up in CPU meters but can be measured with a tool such as LatencyMon. 
 
High-end video adapters designed for gaming can also be a problem for DAWs. The presumption is that video refreshes are what you care about most, an assumption that makes sense for 99% of computer users but not for us audio geeks. They also have fans on them that are not your friend when you need quiet. So if you've got a gaming video card, sell it to the kid down the street who plays Halo and buy yourself a basic card. 
 
Also, your test involves a lot of sampled instruments, which means your disk drive(s) is a major factor. You could be having drive contention and disk thrashing, or even paging occurring. This is likely if all the Kontakt instruments,EZDrummer samples and your project audio are all being read from the same physical disk. The fastest CPU on earth won't help you if your disk I/O can't keep up.
 
It's normal to see all four cores not being utilized. SONAR does an admirable job of load balancing, but there is only so much it can do in that regard. Remember that it's spending 95% of its time executing code that's not even part of SONAR.
 
BTW, on my aged, underpowered 2-core machine I routinely hit 90% CPU here before experiencing dropouts/crackles/distortion.