Is that composition unintentionally set to use the ray-traced renderer instead of the standard renderer?
There is currently a bug that causes Dynamic Link performance to be poor when the main After Effects application is running. (The underlying issue is that the main After Effects application is sending many more messages during Dynamic Link than it needs to.)
The easy workaround is to quit the main After Effects application when using Premiere Pro to process a dynamically linked After Effects composition.
This bug is fixed in an update due to be released in less than two weeks.
Nope definitely set to standard renderer.
Closing AE does seem to increase performance, not a great workaround as the whole point of dynamic link is to be able to edit in one application and have the results dynamically update in the other, however if adobe is fixing it, at least its not forever.