Latency problem

Latency comes from two sources:
-The audio interface
-Latent plugins
 
Sonar has automatic plugin delay compensation (automatic PDC).
If you have a latent plugin assigned anywhere in the project, Sonar delays all other tracks (by the amount of plugin latency... to maintain sample accurate sync.
The solution is to either avoid using latent plugins while tracking... or to temporarily disable PDC while tracking.
 
When playing/monitoring in realtime thru software, you're dealing with round-trip latency.
IOW, if your M-audio audio interface is set to a 256-sample ASIO buffer size, your round-trip latency is more likely ~12ms (which would feel sluggish).
The solution in this case is to use the smallest (64-sample) ASIO buffer size.
 
Round-trip latency is the sum of the following:
-ASIO input buffer
-ASIO output buffer
-A/D and D/A converters
-The audio interface driver's hidden safety buffer
 
The best units yield ~5ms total round-trip latency at a 64-sample ASIO buffer size/44.1k.
Your Delta 66 should be right in this realm.

Thanks guys.  I have reduced my buffer to 64 samples and I'm getting a latency of 1.9mSecs @ 44.1k which is an improvement over 256 which was the default.

But TruePiano still feels sluggish compared to my Sonar 8.5 on win XP using 384 samples and latency of 5.8mSecs.  And its definately slower on playback than when the transport  is idle.

It's correctly picking up my Delta66 drivers for both input and output, recording and playback.