Designed primarily for server and workstation applications, dual Xeon systems have largely led a niche existence. Additionally, their high price made them unattractive for standard users. Dual Xeon systems also required expensive storage modules, special power packs and big, ugly cases. Now, however, the situation has changed considerably.
When we compare, for example, the price of a Pentium 4 Extreme 3.2 GHz against two Xeons with 2.8 GHz, we see that the latter option turns out to be much less expensive. A Pentium 4 Extreme costs $950, while two 2.8 GHz Xeons can be had for $760. Applications that explicitly support the dual processor environments usually operate much faster with two CPUs than with one.