Hello,
 
Moving to X3 resulted in a really annoying problem. Every time i move any VST knob/fader with a mouse I get glitchy sound and CPU overload. It happens not with all of the plugins (Arturia works fine), but a great many of them including anything made by TAL. What is really strange is that it's really a mouse<->VST issue. Tweaking the same knobs via midi controller or even via "assignable controls" section in the synth browser doesn't cause any problems. The problem appears in all projects with "malfunctioning" VSTs (and they all work fine in X2). Any solution / workaround would be much appreciated. Made a problem report, but still wait for a reply...
 
Nick.
 
Windows 7 x64 / Sonar X3 32-bit / Intel Core Quad Q8200 @ 2.33 GHz / 8 GB RAM / NVidia GeForce GT 440 / M-Audio Delta 44
 

I have noticed this in some projects.

I also, have had issues with this...specifically Breverb Sonar placed in the FX Bin...

Now that I've updated to Win 8.1, I now also have an issue with Faders using the mouse.
They jump around like rabbits to the top and bottom, instead of incrementing as they should.
If I use the Mouse Wheel, all is well...

Will keep you posted... 

First, have you updated to X3b?  This sounds like the same type of issue in X2 with moving MIDI notes with the mouse. Any movement, whether large or small, would cause CPU spikes and scratchy sounds to the audio/playback stream. I think it's a Windows vs. Mouse vs. Sonar issue. I say this because I've noticed scratchy audio while using applications other than Sonar when, for example, iTunes is playing in the background. And overall, my computer is very good with audio streaming, i.e. it has low latencies for normal operation (checked using dpclat.exe).
 
Can you try moving clips and notes around to see if this also happens in your projects? If so, then the issue still remains in X3. Also, while doing so, and while moving your knobs on your VST's, run dpclat.exe in the background to see if you get spikes. Thanks!

2:43 AM, thanks for your reply!
 
Yes, I'm using the X3b version. Moving notes and clips doesn't cause any problems to me, so I guess it's a different issue. Dcplat doesn't show any problems at all, so this is not really hardware, something "inside sonar". Actually, CPU doesn't get immediately overloaded. When I try this on an almost empty project with just one synth added, the CPU usage rises from 1% to 15% during the mouse-knob interaction, but there is no overload (but the sound is still glitchy). My further investigation showed that i don't even have to move the knobs to make the sound stutter, i just need to "grab" the knob with a mouse. And, as I wrote before, it all works fine in X2, so this must be something X3-specific, maybe somehow connected with VST3 support implementation etc.
 
Nick.

Does increasing your audio interface's latency make any difference?

Guyz make tikets !!
 
if we want a solid X3C don't let anything passs...

SteveC, 
 
Yes, the glitch disappears when I increase audio driver buffer size to some incredibly high values like 1536 samples / 35 msec. 
 
Nick.

I have to say I am experiencing this same issue, new to me in X3

Hmmm.. if increasing buffers does make a noticeable difference, it would seem that there's some type of graphics/resource interaction taking place.  
 
My system isn't drastically different than yours - Windows 7 x64 / Intel Core Quad Q9300 @ 2.5 GHz / 8 GB RAM / Generic ATI graphics w/ 1GB RAM, although I am running X3 x64.   So perhaps the usual suspects apply - latest graphics card drivers, minimal background processes, try turning off AV software if running, etc.    It might even be worthwhile reducing your graphics settings just as a test; e.g., 16bit color, reduced resolution, etc.   Can't hurt to try!