[reddog]

I am running PT 8.0.3 on mac OSx 10.6.2

processor 2.8ghz intel core 2 duo
memory 8 gb 1333mhz DDr3
Mbox 2 pro - from firewire port ( 800 port - converted to 400 with cable)
External harddrive Lacie 1 TB firewire 800 - run through express card 34 to fire 800 - ( sonnet fire800 pro express card/34)

All recording in saved on external hard drive. Plugs in are what shipped with protools.
Consistently get error message 6101 cpu overload when running VI tracks
HAve tried all possible combinations of Buffer size etc.. on playback engine.
Have upgraded RAM to 8 GB was 4 before.
Have gone through all processes to optimise mac - ie turn off time machine etc...

Questions
1. how many VI tracks could I expect to run at once - I know I can bus them to audio tack and thus disable them.
2. I have tried every thing I can think of to fix this, It will sometimes happen with only 2 or 3 tracksand CPU usage at only 20 %. Very frustrating.
can anyone offer some advice