The concept of fitting normal PC hardware into a tiny package has been proven to work and small form factor (SFF) systems are now commonplace. While most manufacturers target their SFF models at the media PC space, the company that invented the concept, Shuttle, has continued to create SFF systems that are more general purpose PC replacements.

Intel’s launch of its LGA775 Prescott CPUs and i915G chipset put several roadblocks in Shuttle’s path. Prescott is a very power hungry, and therefore hot, running processor, so concerns over supplying enough juice and cooling have meant for a radical redesign of the internals of its XPC.

The end result of this is the Shuttle SB81P. It is larger than most small form factor systems, but only slightly. This extra room has been put to good effect though, as it means that Shuttle has managed to cram in a 350W power supply and free up enough room to add more hard drive bays.

While this renewed internal design is already a radical change, Shuttle also took time to listen to feedback and improve upon nearly every aspect of the design. The end result is a SFF chassis that is completely tool-less, with liberal use of custom made clips and thumbscrews to make installing hardware a breeze. This also extends to mounting hard drives in the system using plastic brackets.

Internal design is important with the SB81P because it heavily influences both the kind of PC that can be built inside it and where the PC can be placed. In order to deal with the heat that is pumped out by the Prescott Pentium 4, Shuttle has adopted a plastic duct to effectively isolate the processor from the rest of the system. The duct creates a tunnel running from right to left at the front of the case, and matches up to air vents on the sides of the cover. This is an incredibly efficient way to manage heat levels, but it does mean that a lot of care needs to be taken when placing the SB81P. To test this we blocked the intake and outtake vents and ran some stress tests on the processor. After about 20 minutes the system crashed completely and needed to cool down before rebooting.

While this problem will only occur in extreme cases, it does mean another hidden problem crops up. In order to ensure that the Pentium 4 does not overheat, Intel employs a technology called thermal throttling. This slows down the processor speed when it starts to run too hot, meaning that PC performance will drop sharply. If the XPC SB81P is not cooling the CPU effectively this is likely to happen.

It is this potential overheating, a problem that lies more on the side of Intel’s CPU manufacturing than Shuttle’s system design, that is our major concern with the SB81P.

Moving beyond the CPU duct we see just how well thought out this system is. Previous models have had the AGP slot on the far left hand side of the chassis, which means that high end graphics cards that need two slots cannot be installed. The introduction of PCI Express in the SB81P Shuttle has positioned the x16 PCI E graphics slot on the far right of the chassis, which gives enough room to install a monstrous video card.

The other standout aspect of the design is the fact that the small height increase over previous models has been used to create space for two SATA hard drives to be added to the system (as well as the usual 3.5in drive bay that can take either a hard drive or floppy). These can be easily setup as a RAID array, or run as separate drives.