Thanks for your reply. I am using East West QL Symphonic Orchestra plug-in, Software Samplers, Effects plug-ins, etc. I also use Reason, Logic Pro etc. How can you tell whether they are CPU intensive/memory intensive? Powerbook can have only 2 gig max. I will have to throw away 512mb chip. (Not really throw away, I could sell on ebay but still I have to go thru all that hassle).