Hi, to check performance on your system try the guitar rig 2 demo from native instrumensts website regarding performance I have cracklings with guitarrig two on my G5 Dual 1,8 with my fireface 400 at buffersizes of 128, thats not good at all.... guitar rig 1 was performing much better here.... I own rigcontrol 2 too, but regarding performaqnce you should get better results with your fireface as your audiointerface, and an aggregated divice will even be worse. additinally, writing automation data with rk2 is not working well over here with logic 7.2.3 Best regards Wolfgang Sperner ----------------------------------------------------------------- Group Buy until Feb 22nd for Virtual Instruments Magazine! See http://logic-users.org/groupbuy/vimag for full details.