Earlier this week, I got a chance to work with a Mac Pro for an hour or so to see how it stacks up against the now-discontinued Power Mac G5. The model offered by Apple for purposes of this quick review was the standard configuration, which has the stock 2.66-GHz Xeon processors, 1GB of RAM, a 250GB hard drive, a single 16x SuperDrive and the Nvidia GeForce 7300 GT graphics card with 256MB of video RAM.

Xeon inside

The dual-core, dual-processor, 64-bit machine is significantly quieter than Apple's previous top-of-the-line machine, the Power Mac G5 Quad, no doubt due to the lower power requirements and dramatically lower heat output from Intel Corp.'s Xeon "Woodcrest" chips. While the Mac Pro's outer casing is not appreciably different from the Quad G5, the inside has been completely revamped. Since the heat output of the new system is so much lower than in the G5, the number of fans has been cut from nine to four, and the liquid cooling system is gone. That leaves much more room for computing components, and having fewer fans means less noise.

Yes, these machines are as silent as they are slick looking, and the internal components are also now much easier to self-service. The DVD drives (you can now have two) are in removable, sliding bays. The PCI expansion slots are easier to populate, with a single, captive thumbscrew holding the bar that maintains the card placement. In other words, there are no more screws to lose and no tools needed to add or remove cards. The PCI slots are all configurable as 1, 2, 4 or 8x slots, and the first slot is a double-wide to accommodate many of the newer graphics cards without blocking another slot.

Additionally, the hard drive bays are lined up across the inside in a configuration similar to an XServe, where SATA drives easily slide out on a cable-free sled. Professional operations will really appreciate the fact that -- unlike the Xserve -- the Mac Pro drives can be upgraded by buying any SATA drive and putting 4 screws in the tray to hold it in place. Now, that's easy.