Although the portability and performance of small form factor systems like Shuttle's XPCs can't be denied, the diminutive cubes aren't perfect. For starters, the majority of small form factor systems offer only one PCI slot. Most users probably won't feel restricted by a single PCI slot, but anyone looking to run a 24-bit audio card alongside a PCI-based TV tuner or Wi-Fi card need not apply.
In addition to the PCI slot limit, most cubes have only one free internal 3.5" drive bay, limiting users to one hard drive. It's possible to run multiple hard drives by tearing out a cube's integrated memory card reader or taking over its 5.25" drive bay, but those are hardly practical solutions.
These limitations are the least of the problems for most SFF systems, though. Since most cubes are sold as barebones systems that rely on proprietary motherboard, case, and cooling designs, you can forget about mixing and matching barebones components from different manufacturers. Companies like Shuttle have changed their case and motherboard layouts slightly over time, too, making it difficult, if not impossible, to upgrade older cubes with the latest motherboards.
Finally, small form factor systems have relatively weak power supplies that currently top out at 250W. With Prescott Pentium 4 processors pulling watts like they're going out of style and the GeForce FX 6800 Ultra sporting two auxiliary power connectors, a 250W power supply is cutting it a little close.
So, while the extreme portability and petite footprint of small form factor systems has enabled and inspired all sorts of interesting system designs, the tiny systems also come with a fair bit of baggage. If only there were a middle ground, a platform that took up less space than traditional ATX or Micro ATX cases without suffering from the limited expansion and upgrade potential of most small form factor barebones systems. There is: Antec's Aria enclosure.
Unlike barebones systems, the Aria is just a case. The Aria comes with a power supply, but the motherboard and processor cooling are up to you. Fortunately, you should have no problem finding a suitable motherboard for the Aria; the case is designed to enclose standard Micro ATX boards as large as 9.6" x 9.6". This compatibility with standard Micro ATX boards gives the Aria a much clearer and more flexible upgrade path than typical small form factor systems. Also, since most Micro ATX boards sport three PCI slots in addition to an AGP slot, it's easy to build an Aria-based system with more expansion potential than the average cube.
To accommodate larger Micro ATX boards, the Aria is a little bigger than most small form factor systems. However, the size difference is actually less than you might expect.
Measuring 7.9" tall, 10.6" wide, and 13.2" deep, the Aria is bigger than the average cube, but much smaller than standard ATX fare. The extra internal space leaves room for three internal 3.5" drive bays, eliminating another gotcha associated with traditional small form factor systems.
With upgrade path, PCI slot, and internal drive bay baggage a non-issue for the Aria, the only small form factor shortcoming left is limited power supply wattage. Antec has an answer for that, too. The Aria comes with a 300W power supply that is a definite improvement over small form factor PSUs rated for 250W or less.
So far, it looks like the Aria addresses the typical shortcomings of small form factor systems. However, in avoiding typical gotchas, Antec has also saddled the Aria with some baggage of its own. Join me as I explore the Aria's triumphs and flaws to determine if this unique take on the cube form factor is right for your next PC.