John
Dave you should have a minimum 8 GB for a 64 bit system.  4 GB isn't enough.
 
You will need to get matched modules too. Unless you can be 100 % sure that any add on RAM will be identical to what you already have. This means not just the same brand but the same date of manufacture as well as the same type. Its best to simply replace it all to up the amount.   

No disrespect to you, John because I know you are only trying to help.  I ported the problem project to another DAW platform, inserted the same exact plugins and continued to add additional plugins until mixing was complete.  I can agree that more RAM is always better than less RAM but (and I may be totally wrong) I would think that a programmer could maximize efficiency and be a good steward of a systems resources when they write their code.  In fairness to SONAR developers, the program I finished the project doesn't have nearly the bells and whistles that SONAR has with it's Skylight interface and touch screen capabilities but I don't use those features anyhow.

If I install my new soundcard and it's drivers exposes a weakness in my system as well, then I will know that I have to make a decision to beef up my DAW from ground up or move on down the road until such time that I can do an upgrade.

Mod Bod, just wondering whether you'd tried the v3.16 2010-12-10 beta Dakota drivers here?:
 
http://frontierdesign.com/Support/Downloads/Dakota
 

 Semi related encouragement:  I am using an "old" emu 1820m PCI  interface with the beta drivers for the newer PCIE interface.
 
Fixed a bunch of crashes in windows 8, and fur shure with x2:  was having computer freeze when exiting X2.   Seems to be the midi part of the interface, which I cannot disable.
 
The beta drivers are working better.  No full computer freezes.  Occasional sonar crash after opening and closing many projects in a short time.

jm24
 Semi related encouragement:  I am using an "old" emu 1820m PCI  interface with the beta drivers for the newer PCIE interface.
 
Fixed a bunch of crashes in windows 8, and fur shure with x2:  was having computer freeze when exiting X2.   Seems to be the midi part of the interface, which I cannot disable.
 
The beta drivers are working better.  No full computer freezes.  Occasional sonar crash after opening and closing many projects in a short time.

Are there input/output entries you could remove the check from in Preferences>Midi>Devices, for the midi port(s) from the EMU audio interface?
 
Bob Bone
 

Mod Bod

John
Dave you should have a minimum 8 GB for a 64 bit system.  4 GB isn't enough.
 
You will need to get matched modules too. Unless you can be 100 % sure that any add on RAM will be identical to what you already have. This means not just the same brand but the same date of manufacture as well as the same type. Its best to simply replace it all to up the amount.   

No disrespect to you, John because I know you are only trying to help.  I ported the problem project to another DAW platform, inserted the same exact plugins and continued to add additional plugins until mixing was complete.  I can agree that more RAM is always better than less RAM but (and I may be totally wrong) I would think that a programmer could maximize efficiency and be a good steward of a systems resources when they write their code.  In fairness to SONAR developers, the program I finished the project doesn't have nearly the bells and whistles that SONAR has with it's Skylight interface and touch screen capabilities but I don't use those features anyhow.

If I install my new soundcard and it's drivers exposes a weakness in my system as well, then I will know that I have to make a decision to beef up my DAW from ground up or move on down the road until such time that I can do an upgrade.

DAW bakers should be aiming to make their products as light on resources as possible, yea, computers move on, but not everyone has the money to out on new ram/processor and such with every revision of the product.
The problem comes when bakers are too busy trying to make something look pretty, whilst forgetting about the core of the program, stability, functionality and as light on resources as possible to reduce the likely hood of latency induced by hogging the systems RAM/processor cycles. Daw bakers should build these programs to run on older hardware instead of building them to suck up the resources of newer systems with higher spec components.

Just following your progress. I _still_ haven't made the move of my Dakota cards to the new 3930K DAW. Reworking our live gig rig to use a new Sony VAIO touchscreen to control a new 16.04.02 got in the way. Re-worked wiring harnesses, building rack enclosures, etc. Need to wait until our summer of camping is done and the kids are back in school.

BB:  The drivers load whether stuff is disabled in sonar or not.
 
Optimizing software:  we all have been complaining about bloat ware for years. It is the result of using high-level languages with compilers. And the quick increase in available hard disk space and computer speed. Most programmers have not cared, or learned, how to use the most compact efficient code.
 
Because of the big advances in hardware miniaturization during the past 10 years, the MS dudes understood they could use the same core code for all types of hardware. To do so they had to optimize the code. This meant actually removing all the ignored crap.  And also optimizing the compilers.
 
Hence the improved performance on existing hardware.
 
But because of this improvement programmers/managers will be less concerned about using tight code.
 
One good bit about windows 8 is how it encourages drivers to be re-written to be stable. Sad some good hardware will be abandoned.

Goddard
Mod Bod, just wondering whether you'd tried the v3.16 2010-12-10 beta Dakota drivers here?:
 
http://frontierdesign.com/Support/Downloads/Dakota
 

Yes, I have those drivers but they show up as 3.15.  I figured that was because it was a beta.  Do you see that in the Dakota Control panel?   I tried updating the drivers just the same and the installer said that I had the most current drivers.  Just the same, I uninstalled the drivers and then installed them again.

Currently, I am able to play the problem project again.  But I've seen the same thing happen after opening the project in SONAR X1 - it will play for a time in X2a but at some point in time, it starts crashing again.

This problem may be moot tomorrow, when my RME card gets installed.  At least I will have drivers created in the same year I'm in.

I am QUITE looking forward to you posting on the results of your new RME interface.
 
I am rooting for you to get some success and stability after all of your suffering, 
 
Bob Bone
 

robert_e_bone
I am QUITE looking forward to you posting on the results of your new RME interface.
 
I am rooting for you to get some success and stability after all of your suffering, 
 
Bob Bone
 

Thanks for your concern but my suffering is minimal.  I don't let these sorts of things slow me down.  I find ways around them and move on.