how to test System Performace??

XBench is not perfect, but it's popular and will at least help give you some idea of how fast your machine is. It includes the ability to see other people's scores so you can compare the speed of your Mac Pro to other similarly equipped ones.

 

I think the reason people say the test is crap is because the results are all over the place. For example, how can a machine with 2GB of ram beat the exact same machine that has twice as much ram?? I ran the test and compared it to another machine with equal components and my machine wasn't even close. Another test showed disk results with a single Seagate drive and they were way faster than my 10K Raptor. My Raptor has a fresh install of OS and applications and over a 100GB of free space, so there is no way that Seagate is going faster.

If a test is not verifiable with acurately measurable results, then it's crap and totally worthless waste of time.

 

Not fast compared to what: the newest model, your friend's computer, the way it performed when you first got it? There are many threads about improving sluggish machines, if that is what you mean.