It distributes the load of running several applications for way better performance. It is not better at running one application unless that application was written to take advantage of multi processors. The newer versions of OSX run numerous applications in the background, by default, and dual processors can help this a lot. I am looking forward to Dual Core processors in all Apples computers, so the mentioned advantages are even in single processors. Roger On Aug 2, 2005, at 9:38 PM, Dan A Currie wrote: > Hello All, > > What is the advantage of dual versus single processors, i.e. dual > 1GHz v. single 1GHz? > > TIA, > > Dan >