Regarding buffers, I thought I'd get a head start by posting a few screen shots from my preferences menu.  Thanks!
 

 

 

 

 

 

If not using touch, you could try, but I doubt that is a significant issue. Services which use connections or analysis are often the ones to watch. The only two which stand out are DropBox, which is listed as stopped, and McAfee. I forget now how often Dropbox syncs itself, but that is one I have only run manually. The DropBox entries could be unchecked. Some services re-enable themselves when you manually start them, so may need to be disabled again (which may be why you have 2, not sure).
 
Are you constantly connected to the internet? The McAfee bothers me a lot, and I have not had time to check that and is late already, but what came to mind would be to disconnect the internet, disable all those McAfee entries, and reboot. Virus scanners can be over-aggressive and analyze everything happening on a computer, so would be good to try running the computer as a DAW without that overhead and see what difference it makes. If it is night/day, changing the settings in McAfee would be a first step.
 
I didn't sign in until late, but need to revisit this. If you get an opportunity to run SONAR with McAfee turned off that would be a good data point. You may even be able to click the icon in your taskbar and temporarily disable it or use a "silent/gaming mode." I will need to follow up with this tomorrow since I am running out of steam at the moment.

Quick update to the above, is the McAfee version installed called "McAfee Security Center"? I just did a quick search for disabling McAfee temporarily, and caught this post on cnet. I am not sure how effective that is. Seems a bit of a PITA, but the advice there was:
 
"Double-click the taskbar icon to open the Security Center
Click Advanced Menu (lower left)
Click Configure (left)
Click Computer & Files (upper left)
VirusScan can be disabled on the right.

Do the same via Internet & Network for Firewall Plus."
 
In your situation, when using the computer as a DAW, simply unplugging the Ethernet cable will prevent most "phone home" routines. The McAfee part could either be disabled per above (if works), or from the msconfig dialog (which may also not work). If you get a moment to try running SONAR without being connected to the internet and McAfee offline, it would help to see how much McAfee is affecting you (there are actually free AV programs which do fine for most usage out there). Note: you may also need to disable the new Start Up screen within SONAR preferences, as I recall an issue with that enabled and no active internet connection available for certain versions (but forget which ones).
 
For AV programs, I have run Avast in the past, which can be temporarily disabled in the task bar, and also has a "silent/gaming mode" to it. One thing to also note is that multiple AV programs will also analyze each other, so you want only one enabled that suits your needs (and remove/disable all others completely). That is more FYI after the McAfee overhead is understood.
 
Win10 also throws a kink in the works for me, as I am not sure of specifics for that version yet.

Pesky sleep, who has time for it! (:
 
Eventually, I plan to disconnect the internet all together.  The only reason it is plugged in now is to avoid running Sonar in demo mode.  I upgraded to Sonar Platinum by signing up for the monthly payment plan and it is my understanding that I must stay online until I am paid off.  I could be wrong of course.  I will look into obtaining offline permissions now. 

I thought you only needed to connect once a month to validate?

I must not have refreshed the page before typing my last post because I am just seeing your recent post now.  So, if my post doesn't make sense that would likely explain it.  I double checked and it appears that I have McAfee Livesafe.  I couldn't find any mention of Security Center on my CPU. 
 
I will try running sonar without the internet plugged in.  Even in demo mode I should be able to start a fight with processing!  If McAfee  is the issue, I would prefer to remove McAfee all together in place of another recommended AV program such as Avast.   

I can honestly say that after about a week my computer seems to be handling SONAR far better than it was when I first posted this plea for help.  I tried without internet for about two days before I couldn't take using the demo any longer.  Which reminds me, cakewalk support has never taken this long to get back to me.  I emailed them requesting input on offline authorization.  Oh well, I'm sure Christmas is busy for them.
 
But I'm getting off track... 1 audio engine failure when offline compared to 3 (on average) a day online with my AV.  That's improvement!
 
I just had a crash a few minutes ago.  It occurred when I hit "Control-z" and then "R" too quickly.  Between this and when I am using the step sequencer, I think they are the most common "last thing I was doing" scenario pre crash.  Not sure if that means anything.
 
Take care!

I finally had a chance to use Sonar offline (user error).  I shut down the computer, unplugged my Ethernet, started the CPU and disable all McAfee software.  Restart again. I notice that some of the McAfee services had re enabled themselves.  Not all, just some (AP service, Firewall core service, etc).  I used SONAR offline for a few days and did notice the crashes are less frequent, however; they still exist.  Either the audio engine stops working or I get the sonar is not responding error followed by a full crash.  Same culprits.  It happens when I ctrl-z and hit space too quickly (which I've tried to slow down on), using the step sequencer (most audio engine stopped working), and for the crashes it follows either playback stop/start.
 
I am definitely in a better place than I was.  Thanks for all the help!  Still, I cant help but second guess my decision to pump a ton of money (a ton by my standards may be less to others) into a new computer and still have to deal with crashing.  I know its not a sonar issue, but it is related enough whereas Dell support give me the "it should work" line. Amy suggestions welcomed and appreciated as usual.  One thing to note is that I increased my buffer to 512 at Melodyne editors request.  I believe ASIO had me at 256 previously.  Maybe this will help....
 
Happy holidays everyone!

I had MacAfee or however you spell it, and had some issues years back with it, so I switched to Avast's free version, and have never looked back.
 
Avast has a nice small memory footprint and never causes me issues with Sonar, and I can temporarily suspend it if needed.  It also has a means of excluding specific folders from being actively scanned, and this helps too - to keep it from scanning the Sonar folders and my sample libraries.  
 
Perhaps your MacAfee AV software also allows exclusion of particular folders, and maybe that would help some too.
 
Bob Bone
 

Thanks Bob!  I will check on the exclusion feature in McAfee, however; you are another addition to a growing list of individuals with little good to say about McAfee's compatibility with Sonar.  Since I have no real commitment to McAfee (it came with the computer), I think I might just go for an uninstall.  You are also not the first to mention Avast, so I am tempted to follow in your footsteps in this regard as well.  All in all, as soon as my computer is running the way I think it should I will probably unplug the internet as I have in the past and just use my laptop for browsing.  Security is not my highest concern.  I bought this computer for Sonar specifically.
 
Take care and thanks again!
 
Jake