Thanks for hanging in there.  I am a bit brain dead at the moment, having just spent the last 25 minutes typing as fast as I can for a different thread, so please bear with me.

Oh, and thanks for posting back on your redraw disabling, disappointing as that ended up being.

I believe that Core 1 is always going to be the hardest hit, but the spike causing dropouts is way uncool.

Have you tried running DPC Latency Check without Sonar running?  I am quite curious as to what this program reports after running for maybe 3-5 minutes on the min/avg/max latency detected on your system.

Also, I found it helpful to go through Device Manager and look at disabling things not needed for audio streaming.

Perhaps if you have not done so, can you try removing any graphics cards and just running basic VGA?  This would rule out any graphics interference.

Also, and extra software running as background services (antivirus, etc) might be interfering with things - something else to look at.

I hope I have not just repeated a bunch of stuff that was suggested earlier (maybe even earlier by me, yikes).  I just got back from dealing with a couple of friends losing their dog to a car, and it was pretty exhausting.

I WILL continue to look at things to assist you, and hope to here back from you on any of the above you have not yet tried.

Bob Bone

Edited to remove my cranky initial response to Theycallmefree's intermingling of threads.

Bob Bone