The cube's guts
Now that we've got the specs outta the way, we'll give you a look into the belly of this Lilliputian beast. The SB51G incorporates Shuttle's excellent I.C.E. Tech heatpipe cooler, which effectively combines the XPC's rear exhaust fan with the CPU cooler fan, eliminating the need for a separate CPU cooler fan. The one remaining fan is a nice, quiet Sunon job that plugs into the motherboard for power, and the motherboard controls the fan's speed based on feedback from its thermal sensors. All told, the SB51G is startlingly quiet compared to your average desktop system. I let the system crank away at Folding for 20 hours or so, and the thermally-controlled fan only kicked up its speed and noise level slightly.

The SB51G's insides, including the heatpipe cooler and integrated rear exhaust fan

As if the heatpipe setup weren't clever enough, Shuttle has also incorporated a heatsink retention mechanism that requires only thumbs and fingers to install or remove. Combined with Shuttle's ample use of thumbscrews everywhere, it's possible to remove and reinstall the cooler without the aid of a screwdriver, provided there aren't any cards in the PCI or AGP slots.

Shuttle's purty, purty heatpipe. The copper surface goes on the CPU.

I do have a gripe about this system's cooler. Fan speeds and temperature thresholds are set in the system BIOS, but for the brief instant after a boot or reset when the system's BIOS hasn't initialized yet, the SB51G's fan cranks up to its top speed. Then, a second or two later, the speed will drop as the BIOS kicks in and takes control. It's annoying. I'd rather the default for those first few moments during boot were a little bit slower fan speed. I'm picking nits, but that's what I'm left to talk about here.

Quarters are cramped inside, but everything fits

The SB51G's lift-out drive cage

The cube's drive cage lifts entirely out of the system, so installing drives is at least as easy as in a larger enclosure. The drive chassis includes one internal 3.5" drive day, an external 3.5" drive bay, and an external 5.25" bay. Assuming we avoid installing a floppy drive, that's room for a pair of ATA hard drives and a CD-RW/DVD combo drive, which ought to be enough for most folks. Personally, I'd find that combination of drives a little constraining, but then I'm not most folks.

The system's PCI and AGP slots are, naturally, tight fits, but they work. Even an NVIDIA GeForce4 Ti 4600 reference design-based card, which is utterly monolithic and lacking in human scale, will fit into the AGP slot. A Radeon 9700 is a piece of cake. The PCI slot ought to fit most reasonably sized cards, as well.

Incidentally, the SB51G's built-in Intel "Extreme Graphics" are dog slow in 3D games, but its video signal quality is much better than the SiS graphics integrated into the SS50. In fact, if you're not into 3D gaming or applications, and if multi-monitor configs aren't your thing, there's no good reason to fill that AGP slot. The integrated graphics will serve you well.

The PCI and AGP slots