I am getting some annoying audio clipping when running an arrangment of just audio tracks and a load of waves plugins. I have looked at the mac activity monitor to see if it was a CPU overload but it was not, also not using loads of ram so i’m a bit confused. I run a Mac Pro 2 x 2.26 GHz Quad-Core with 12 GB Ram. Any ideas anyone? 
Goto Menu > Devices > Device Setup > Select your audiocard and press Control Panel button.
Increase buffersize.
BTW. Your amount of Ram is only gonna be used if you’re running C6 in 64bitmode.