Don't worry. The latest update for the Mac Pro pretty much lives up to expectations. In some ways, the basic quad-core 2.66-GHz Mac Pro that Apple sent over for review screamed. But it falls short when it comes to great expectations of across-the-board performance leaps.

With this iteration, the Mac Pro takes a significant step forward by , leaving behind the previous model's Harpertown and Penryn chips. (Yes, they're all officially Intel Xeon processors, but Intel's nomenclature is so arcane that it's better to go by those code names to keep the models straight.) For $2,499, the entry-level Mac Pro offers a quad-core 2.66-GHz processor, 3GB of DDR3 EEC memory, a 640GB hard drive, an 18x double-layer SuperDrive, and an Nvidia GeForce GT120 video card. For $800 more, you get two 2.26-GHz quad-core processors (for a total of eight cores) and 6GB of RAM. It's a hefty price bump, mostly for the additional CPU; Intel's newest processors still command a premium cost. There are also a variety of CPU options: Moving to a 2.93-GHz single quad-core Xeon adds $500 to the price of the base model -- or you can get two of them for $2,600 extra in the top model.

If those prices seem high for a personal computer, they are. Granted, these Mac Pros approach performance numbers previously seen in Unix workstations costing in the five figures. And they offer Apple's traditional build quality, not to mention the vertical integration of hardware and software that can avoid driver updates and conflicts. But price does focus attention on value and on whether those Apple advantages are worth the cost.

Various commodity PC makers are starting to roll out their own Nehalem offerings at much lower prices. Lenovo, for instance, has put out workstations with Nehalem-based Xeons; its single-CPU, quad-core S20 starts at $1,070, with the eight-core, dual-CPU going for $1,550. Of course, these are bare-bones prices, with the features and expandability that are already built into the Mac Pros sure to cost extra elsewhere. But the ability to order a bare-bones model is something that has always been attractive to businesses. So tote up the balance sheet if you're comparing this workhorse with others.

Nehalem, yes, but lower clock speeds