This is more of an "Oh no not again" type post, ...
I am constantly amazed at the number of escalations that make it to the performance group with this as the problem.
It really is a case of an unrealistic expectation and knowledge of what the machines excel at.
The most recent of these to cross my desk talks of a customer concerned that a dual core 2.5GHz x86 based box loads data into an Oracle database much faster than his shiny new T5220.
Until such a time as Oracle makes their SQL Loader run multi-threaded (which may bring in problems all of their own) this will always be the case.
The design of the system is such that it will run single threaded applications much slower than the x86 counterparts. These machines, however, come into their own once we enter production and start getting lots of parallel requests on the database. As we are running far more cpus, the load on the database must be much higher before we start to see any significant degradation.
The question that really should be asked here is, "Where do you want your performance? In the database load that you will do once, or in responding to production queries?"