The upgraded desktop is available in a quad-core 2.8GHz Intel Xeon “Nehalem” processor with 3GB of RAM for $2,499; an 8-core machine with two 2.4GHz quad-core Intel Xeon “Westmere” processors and 6GB of RAM for $3,499; or a 12-core system with two 2.66GHz 6-core Intel Xeon “Westmere” processors and 6GB of RAM for $4,999.
With the latest Intel Xeon processors and up to 12 processing cores, the latest Mac Pros are up to 50 percent faster than their predecessors. My own testing puts the 12-core “Gulftown” high-end processor at up to 80% more throughput than a 6-core high-end AMD Phenom II. Benchmarks here.
Finally, Mac Pro customers have the option to order a 512GB SSD for the ultimate in reliability and lightning fast performance.