travel has changed over the years. some things are faster and some are slower. it takes longer to get through security but it takes less time for ticketing. you can print boarding passes the night before saving the airlines money on printing and papssengers time in line. the airlines have optimized plane capacity to an art. imagine doing the same thing for computing. if we had a jumbo jet and a fleet of prop planes how would we schedule passengers. the same would be true for a 4 way multiprocessor with 8 gb of ram and a bunch of desktops. forunately we can pool resources and make the prop planed fly to the same city and share seats as if it were one plane. this is the corrilary that i can make for rac and grid features from Oracle. instead of buying expensive multiprocessors you buy smaller processors fully loaded with memoey. the database manager colates these machines to look like one big computer. the same is true for a web server farm and vmware.