Shuttle may no longer have the small form factor market all to itself, but the company that invented the concept still takes first place when it comes to design and technology. Not only were its SFFs the first to offer Intel's 915 and 925X chipsets in a small case, but Shuttle has now produced the first Intel 945G-based design on the market. This makes the SD31P the first small form factor on the market that supports Intel's new dual-core CPUs.
The SD31P uses the P-series chassis that we first saw used by the Intel 915G-based SB81P. At that time, we were a little sceptical about whether this really was a step forward from the classic G-series chassis, but the design has matured, and the SD31P sees some important improvements. For a start, the finish is a much more classy matt black. The two runners used to hold hard disks at the top of the case now come fitted as standard, and they make installing a hard disk very easy. However, only S-ATA power and data cables are accessible at the top, so make sure you have a S-ATA hard disk to hand.
Beneath the plastic hard disk runners is an aluminium drive caddy, which is capable of holding a single 5.25in drive, complete with EIDE cables. Fitting a drive is a screwless procedure, involving a confusing collection of little plastic railings. Aside from a pair of railings for a 5.25in optical drive and a 3.5in drive, there are two more for a floppy, and another set for a hard disk. You can fit two hard disks at the top of the SD31P, and either a floppy or third hard disk beneath the optical drive in the drive caddy.
The only time you'll need to get the trusty Philips-head screwdriver out will be for detaching and reattaching the processor heatsink. It uses Shuttle's tried-and-tested ICE heatpipes, but comes with a 70mm fan attached on the right-hand side. On the left, a 92mm fan ensures that air is drawn across the CPU from right to left, with grilling and ducting keeping processor heat away from all other components. It isn't the easiest system to install, but it works well once it's in place.
The heatsink system is the same as that of previous P-series Shuttles, and the rest of the cooling strategy is identical as well. This was something that particularly surprised us when we first saw it in the SB81P, as Shuttle had moved from the single 92mm fan used in the older G chassis to the more complex arrangement of four fans seen in the P-series designs.
However, experience has shown us that there's considerable method to Shuttle's multifan madness. Manually crank up the fans to 100 per cent and they scream blue murder, but in everyday use they never even get close to that. In fact, the SD31P ran amazingly quietly, even with our dual-core test CPU. One of the most irritating noises in the old designs was the 40mm fan on the PSU, but on the P-series models, the PSU is cooled by a slower-revving 80mm unit instead.
The SD31P has numerous other touches that give it a real sense of polish. The on-board audio is a fully-fledged Sound Blaster Live! 24-bit system. This offers 7.1-channel sound, and there's optical S/PDIF in and out. Intel's latest ICH7R Southbridge is integrated on-board too, so the three internal S-ATA ports are all S-ATA II compatible, and can be configured in a Matrix RAID array.
Shuttle hasn't skimped on the power supply, either. The SD31P packs a 350W SilentX model, offering twin 17A 12V rails, but a maximum of 18A on 3.3V and 5V. The power is output to two Molex and three S-ATA plugs, making most drive configurations possible. Best of all, PCI-E power has been routed to just where you need it - right near the back end of the 16x PCI-E slot.
Shuttle claims the SD31P will power any graphics card you can fit in it, and you can just about squeeze in a card with a large Arctic Cooling HSF too.
PERFORMANCE
Last issue we introduced our all-new 2005 line-up of CPC benchmarks, and upgraded our reference PC to one based on a 2.8GHz Pentium D 820. The first Intel system to be put through our upgraded benchmarks wringer was Abit's high-end, Intel 955X-based AW8-MAX. The 955X chipset includes MPT (memory pipeline technology), which supposedly makes it faster than the more mainstream 945 chipsets. Previously, we've been sceptical about vague high-tech voodoo like this, but the 945G-based SD31P was actually slower than the AW8-MAX. It scored 1.06 overall, compared to the AW8-MAX's 1.09.
We weren't expecting a huge benefit from overclocking, but Shuttle has included plenty of options in the BIOS. The FSB can be varied between 133 and 355MHz, the CPU voltages range from 0.825V to 1.5875V, and there are memory and chipset options too. You can boost the DDR2 to 1.9, 2 or 2.1V, and the chipset to 1.7, 1.9 or 2.1V. First off, we pushed the FSB to 230MHz, without changing any other settings. This boosted our Pentium D 830 test CPU from 3GHz to 3.45GHz. Given that this was so easy, we decided to push it further, and achieved a stable overclock of 240MHz FSB. This required raising the processor core voltage from 1.26V to 1.425V, and the chipset and memory to 1.9V. We also pegged the DDR2 to 533MHz to compensate, in case the high FSB was pushing the memory clock out of its range. This moved the processor up to 3.6GHz, and boosted the overall benchmark score to 1.29.
As the SD31P uses the Intel 945G chipset, it features on-board graphics in the form of the Intel Graphics Media Accelerator 950, which features four pixel pipelines and runs at 333MHz. Accelerator might be its name, but it's still stuck in first gear, and isn't up to playing modern games.
Fortunately, as we mentioned earlier, the SD31P has a 16x PCI-E slot, so we slotted in an Nvidia GeForce 6800 GT. This powered the system to an average of 55fps in Far Cry at 1,280 x 1,024 with 2x AA and 2x AF. If you have any accident- prone and wealthy great-uncles then now would be a good time for you to inherit, because you could easily fit a GeForce 7800 GTX into the SD31P.
CONCLUSION
The SD31P has a few drawbacks: it isn't cheap, and its use of the 945G chipset means that it's slightly slower than the 955X boards we've seen.
However, it still overclocks well, and has more than enough room inside for the kit most people need. There's space for three hard disks, a dual-slot graphics card, and it can take most of the new dual-core Pentium CPUs (aside from the stupidly priced Extreme Editions, which only work on 955X boards). Performance isn't quite as nuts as the SLI SN26P from last issue, but on the Intel side of the fence, the SD31P is about as good as SFFs get.
