We all know Mac Pro's performance comes for a price, but think about this - "With four cores on one die and an integrated memory controller, the new Quad-Core Intel Xeon “Nehalem†processor boosts performance nearly 2x." Take that, add Mac OS X into the equation, and you get one of the fastest desktop computers for the average Joe...although most Mac Pro users are anything but the average Joe.
The fastesc Mac available got incredibly fast, with DDR3 memory fed by two 2.26GHz, 2.66GHz, or 2.93GHz Quad-Core Intel Xeon 5500 series processors in the most expensive models, and up to 4TB of internal storage. The video cards available are the NVIDIA GeForce GT 120 with 512MB of GDDR3 memory, and the ATI Radeon HD 4870 with 512MB of GDDR5 memory, both using the PCI Express 2.0 slot. The problem for ATI fans is that the Mac Pro doesn't come with support for a CrossFire setup, but only for two, three, or four NVIDIA GeForce GT 120 cards in a SLI setup.
The default setup of the 8-Core Mac Pro, the fastest Mac series so far, includes two 2.26GHz Quad-Core Intel Xeon "Nehalem" processors, 6GB (six 1GB) memory, 640GB hard drive, the 18x double-layer SuperDrive and the NVIDIA GeForce GT 120 graphics card with 512MB. The price? $3,299, with free shipping! Ouch...
If that one is a bit out of your budget, you can get the slower Quad-Core Mac Pro, with a single 2.66GHz processor, 3GB of memory, and the same remaining components as the 8-Core model, for "just" $2,499.
Obviously, if you start messing with those setups to get the best for your needs, you may end up with a $5,000+ Mac Pro, but let's forget about money for a moment - having the fastest Mac around is really worth any price, at least to some people, don't you agree?