Also, it is not clear yet exactly what is going on with whatever project you may have running, where Sonar is behaving with poor glitchy performance.
So, if you have a project and it loads, then playback is glitchy, try temporarily disabling any effects plugins that project may have loaded. Sonar has a handy shortcut Key Binding that will toggle the bypassing of all plugins on or off - and that is to hit the letter 'E' on your computer keyboard, in an open project. The first time you hit it, Sonar will bypass any loaded effect in the whole project. IF when you do this the glitches go away, then it is a good indicator that one or more of the plugins loaded into the given project is behaving problematically for the Buffer Size the project is currently using, or possibly that one or more plugins is otherwise having some sort of issues.
(By the way, hitting 'E' again will turn all the plugin effects back on - whenever I do this, I just close the project without saving, so I am never accidentally saving a project with effects turned off).
Anyways, please review the above, and try it, if desired, and post back with results.
The reason i am suggesting looking at the above, is that SOME effects plugins are just NOT meant to be used during recording, but instead are meant to be used when in the MIXING stage of a project. Some of the more robust plugins use something called Look-Ahead Processing, or otherwise chew up a bunch of CPU, and to properly use these, you really need to jack up the ASIO Buffer Size, (I record with an ASIO Buffer Size of either 64 or 128, but when I move on to mixing, I crank up that ASIO Buffer Size to 1024 or even to 2048).
The general approach most folks seem to take is to record with a really small ASIO Buffer Size, and then when ALL done with recording and ready to mix (with those power-hungry mixing plugins), they routinely CHANGE that ASIO Buffer Size way high, like I do, to something quite large, like 1024 or 2048. And when they move on to another project (back to doing recording), they will switch the ASIO Buffer Size back down to something really small, like 32/64/128, depending on their audio interface.
The larger buffer size when mixing allows for these more resource-demanding effects plugins to have enough buffer to do what they do, such as Perfect Space, which is a convoluted reverb, and it reads ahead to know how to apply the reverb effects - and doing so means it really needs a big big ASIO Buffer Size to do this heavy-duty work.
I hope the above makes sense,
Bob Bone