SwarPlug is very slow when used with CakeWalk using DirectXer?

Yes, this is a known issue. We suggest that for using SwarPlug with Dxi compatible sequencers (like CakeWalk) one should use CakeWalk adapter. This has been tested successfully without any problems.

CakeWalk Sonar already comes with a VST Adapter using which you can use VST plugins like SwarPlug in Cakewalk