SilverStone SG01

We've been used to seeing small-form-factor PCs emerging over the past few years, but German manufacturer SilverStone has produced an intriguing variation. Smaller than a mini-tower case yet significantly chunkier than a Shuttle system, the SG01 almost deserves a category of its own, such is its unusual size. The concept is to offer a small form factor to those who don't want to lose the flexibility of a desktop PC.

Choice isn't something small-form-factor PCs commonly provide, coming pre-equipped with a power supply and custom motherboard at the very least. Neither is present in the SG01, leaving you with the barest possible chassis and much more choice - removing the cover reveals enough room for a microATX motherboard. The range of available boards in this size is growing all the time, and this immediately sets the SG01 apart from its smaller brethren.

The extra space also makes building the system far less fiddly. Following the recommended assembly order, the internal 3.5in drive bay is the first to come out, sliding easily once the two screws are removed. It has an 80mm fan mounted on one end to draw air from a side vent and across the two hard disk bays before being expelled from a similar vent on the other side.

Once the motherboard and its CPU are secured in place, you'll start to appreciate just how unique the SG01 is. There's room for a standard ATX power unit of your choosing, opening up the field to include higher-rated or passively cooled models. You'll need to be a little selective, though, as the PSU fits immediately above the CPU cooler and you don't want hot air being pushed out of one and straight into the other. That means power supplies with base-mounted fans are best avoided.

There's more flexibility to be had elsewhere too, with space for two full-sized optical drives, as well as four expansion cards, although they're accessible only after you remove the rear 60mm exhaust fan. With its tiny screws, this will prove to be quite an annoyance if you change your system components with any regularity.

The SG01 can accommodate two double-width graphics cards for a potential SLI setup, although as there are only four slots this will leave no space for any other cards. The outer card can make use of one of the many vents in the case's side, but the inner card will need extra cooling. Thankfully, there's an empty 60mm fan slot in the roof directly above the expansion slots, which could prove handy in the case of any other hot-running expansion cards.

A slight layout problem comes from the cross-case orientation of the hard disks. SATA disks will be fine, but if you plan to use IDE disks you won't be able to connect a single cable to an optical drive and a hard disk at the same time, as their rear connectors aren't close enough to each other. The sheer number of cables snaking from an ATX PSU also causes problems, as there isn't much dead space to stow them away and improve airflow.

Elsewhere, the cables from the front panel are long enough to reach any part of the case, which allows them to be tucked into spare gaps out of the way. You can then slot the 3.5in drive bay back in place beneath the optical drives. Once that's done, the internals are certainly tight, but still positively roomy compared to an SFF case.

Unfortunately, once running, the only fan drawing air into the case is the one mounted in the 3.5in drive bay, which blows the majority of its air directly out of the vent on the opposite side. This leaves the numerous side holes as the only other means of ventilation, and the graphics card and power supply unit create a partially enclosed area around the processor, which doesn't get much cooling at all. When working hard, that lower rear corner of the case can become hot to the touch, but temperatures stayed within reasonable limits even when putting the system through its paces - and that was with a fully loaded 3.2GHz Pentium D system. The good news is that we found the SG01's fan noise to be surprisingly minimal - the fans we added were notably noisier than the fans supplied with the case.