I have a very tight deadline to mix as whole album. Started mixing a song. My CPU usage meters usually barely register more than 10-15% when I'm fully loaded. Mostly UAD plugs so not much CPU requird there. No VI's in the project. All audio tracks (around 40 of them). This problem started yesterday. As soon as I open the project my CPU meters are dancing over 50-60%. The result is constant dropouts and the video card isn't coping so my tracks meters are useless as they are not moving in time with the music. I switch from Track View to Console View and it can take up to 10 seconds for the screen to redraw. Basically unusable.
 
I wondered if there was a bug in the project. So I copied all the tracks including their settings and plugs and pasted them into a new project. Problem solved. My CPU meters are back to barely registering. Hooray, I think. I've opened this new project up again today to continue work and after about 20 minutes the problem is back. Once the problem occurs it will not go away. I open a different project which is just as busy tracks and plugs-wise and it is fine. No issue. Come back to this project and straight away the CPU meters jump up to 50+%.
 
Can anybody help. Any ideas what is going on here?
 
 
 

I tried a little experiment. I pressed the FX bypass button on. So all processing off. the CPU went down to zero. So I turned it back on again. It jumped straight up to 50+% again. So I went along my tracks turning off each effects bin. It made virtually no difference (but why should it, they were nearly all UAD plugs).
So next I went along each channel switching off the ProChannel Global power buttons. And that did the trick.
So clearly the issue is coming form the Pro Channel plugs. The thing is I don't really use the Pro Channel plugs except the channel EQ on maybe half of my tracks. The reason I don't use Pro Channel apart from the EQ is because despite nearly a decade of Mackie Control users asking them to sort this out, Cakewalk still haven't bothered making it possible for you to be able to control anything other than the top module (but that's another story).
I now know what is causing the issue, but I don't know why. It's never happened before. As you know the Pro Channel is turned on by default as are several of the modules within it on each track. I can go through each Pro Channel and remove all the modules I don't want and only turn on the ones where I do use the EQ. The thing is I like the channel EQ. It is one of the design elements that helps SONAR stand out from the crowd, being able to see your EQ curve on each channel in Console View without having to open plugins is great. I should at least be able to carry on working using these steps, but if anyone has any other ideas why this should have suddenly become a problem when it never was before, I'd love to hear.
Cheers

Perhaps you have exceeded the limits of your system resources? Have you tried freezing tracks you are done working with?
 I've always found this helps considerably relieving the CPU and the UAD of working too hard performing unnecessary processing tasks.
 While the UAD does decrease the CPU's processing load enormously, everything still has to flow smoothly through the buss.

You are probably light years beyond this response - but I have to ask the simple question - when was the last time you defrag your computer - just a simple thought with so much happening and the project pulling from different  places/drive/s - just saying or thinking out loud.

Is this a laptop, or does your desktop have any power saving features like C-States?
What's your interface buffer size set to? Does the situation improve if you increase it?

I thought defragging an SSD was a no-no

It is, please don't do that, there are no gains and significant drawbacks

Are you still using an Intel Pentium 4?