When I use Kontakt 5 (3 instances), I notice my 1st thread (core) is significantly higher than the other 7 when watching the performance module in the transport bar. I get audio crackles even though my buffer setting is at it's highest (1024). Vienna Ensemble loaded with 4 large sample libraries doesn't do this. Anyone know why and how to fix using Kontakt 5 in Sonar X3 without it causing high spikes in the 1st thread of my 8 threads? Appreciate your time and advice.

Kontakt 5 is my go-to sampler in SONAR and I often run multiple instances at 128 samples or less without problems. Make sure you have the latest Kontakt update. There was one update in particular that made the difference between "argh!!!" and "ahhhhh!"
 
I'm not at my music computer right now but there are several system customization options in Kontakt, experimenting with those might help.

Thanks for your reply Craig. Yes I have the latest Kontakt version (as of 3-4 weeks ago). If you get some time, giving me some advice on how you configure customizations options in Kontakt would be very helpful and appreciated (I've read the Kontakt manual and tried several options). Also, optimization of my Windows 7 to run Sonar efficiently has been an ongoing struggle (would Windows 8 help?). Can you refer me to any links or posts that address the issue of optimizations, specifically for Windows 7 and Sonar? I've tried the usual Windows and Sonar suggested optimizations from their web site without much improvement. I shouldn't be having these issues with my screaming computer (see my signature info). I can't figure out (neither can ADK computers audio expert support) why "only" Kontakt makes my 1st thread spike into the red a lot causing crackles and audio dropouts. I am running about 7-8 Gbs of samples within Kontakt (total of 3 instances) and about 3-4 Gbs within Vienna Ensemble Pro and have a total of 16Gbs on my system. Would more RAM help or do you think this is a CPU problem? ADK audio tech support claims that Sonar hasn't really addressed effectively the issue of thread and core management/optimization as Cubase and other DAWs have. Thanks for your time. I love to use Sonar as it makes operational sense to me and is easy to use. Only wish I could rely on Sonar to be more efficient and stable. I have hope in X4 coming up though!

http://forum.cakewalk.com/tm.aspx?m=2382979
 
You may find the above helpful. 

Thanks John, but your link didn't help my issue. I think I'll try different buffer settings in the DFD options of Kontakt. Supposedly, the default (60Kb) is sufficient when using SSD drives for samples. Maybe a higher buffer setting will transfer the load from my SSD's to RAM. But I shouldn't have to with SSD's.

You may want to lower your buffer somewhat if this is an ASIO buffer. Too high or too low can cause similar problems. 

What's your OS and chipset? Try turning off Intel speedstep (or AMD powernow) and updating your chipset drivers.. Cheers..

Swapped my out my 16Gb 1600KHz RAM for 32Gb 2133 KHz RAM and updated the XMP profile in my BIOS to match the new RAM and wholla! Also lowered my sample rate from 192KHz to 96KHz. Now can run more Kontakt instances and able to lower my buffer setting as well. Thanks for all your input and suggestions. Case closed!

Milton
Case closed!

Cool...but now you've given me an idea for another thread.