Verdict: Ditch your space-guzzling tower for this dinky PCI Express box
We all have a tendency to over-specify our needs when we get something new. Take, for example, suburban parents on the school run. Instead of driving a small hatchback and stuffing their screaming snot-nosed sproglets in the back, they often insist on driving something stupid such as a Land Cruiser or, even worse, an actual Humvee - vehicles designed for conveying military personnel through some of the world's harshest environments.
You can draw a certain parallel with computers as far as size is concerned. Really, what most people need is a good small form factor (SFF) chassis, but they're often ignored in favour of larger cases because they're thought to offer a better upgrade path. However, the irony is that people who worry needlessly about upgrading their PCs are often the same people who leave the actual task until their hardware is obsolete, necessitating huge changes that a large case doesn't protect against. What they really need is a system that offers upgradability and flexibility when it comes to the processor and memory, and not acres of space they'll never use.
This is where the Shuttle SN25P comes in. It's based on the nForce4 chipset, and supports Socket 939 Athlon 64 processors, so it has a long life ahead of it. Socket 939 is the current focus of AMD's CPU development, meaning faster processors should be available for it for some time to come.
After canning the Athlon 64's original 940-pin socket, and relegating Socket 754 mainly to the budget Sempron, it's likely that all new AMD processors will fit into this system.
There's also plenty of room for drives, as the SN25P is able to hold three 3.5in hard disks. These bays could provide over 1.5TB of hard disk space if it was required. In addition, there's a single 5.25in bay, so if you must have two DVD drives, then the SN25P isn't for you. If you can live without making disc-to-disc copies, though, the SN25P has many other features.
One such feature is the VIA Envy 24PT eight-channel sound chip, which is a step up from the usual on-board audio.
However, the most exciting feature is a 16x PCI-E slot, which is located on the right-hand side of the motherboard instead of the left. Although this sounds less than interesting, it means you can use a double-slot graphics card. This would obscure the SN25P's 1x PCI-E slot, however. A silly oversight is the lack of a PCI-E graphics power plug, so you have to use two of the Molexes for the graphics card, or use a splitter.
If any of the SUV drivers among you point out that there aren't enough Molex connections to go around, we'd agree with you. There are only two, and that's because the SN25P is ready and waiting for S-ATA drives. In all, there are two Molex connectors, and three S-ATA power connections. All this will, at a pinch, power three S-ATA drives, an EIDE optical drive and a graphics card, although you'll need at least one Molex splitter if you intend to use a graphics card that requires a PCI-E power connection. To fit our EIDE hard disk and EIDE optical drive, we required yet another splitter.
While the lack of free Molex connections is irritating, it didn't cause undue concern. What did, however, was fan noise. The older G-series Shuttles are typically cooled by two fans, so how loud will the Shuttle SN25P be, considering that it has six?
Surprisingly, the answer is not too loud. This isn't because the fans are particularly quiet models, but because the SN25P has good fan control. P-series Shuttles have eight speed levels on the CPU fans, allowing the BIOS to scale them back to keep them quiet. If, however, in a fit of madness you do increase the fan speed on all the fans to 100 per cent then you'll realise that the SN25P is capable of keeping a fast PC cool and driving you absolutely mad at the same time. The maximum speeds of the fans are painfully high. The 70mm HSF intake fan maxes out at 3,800rpm, and its paired 80mm fan, which sits at the end of the HSF wind tunnel, has a top speed of 4,200rpm. These two fans at full revs would be enough to break most people if used as a torture device. Add to these the twin 60mm case exhaust fans, with their maximum speed of 3,900rpm and you quickly have a cacophony of sound.
The 60mm fans should never hit maximum speed, though, as they're mainly used to cool the SN25P's hard disks and only need to remove a small amount of heat. They're a godsend, though, as without them your disks may overheat. This was an issue with Shuttle's XPC SB86i, as it has a similar internal layout to the SN25P, but lacks the twin exhaust fans.
PERFORMANCE
The SN25P's high-powered cooling abilities, relatively meaty 350W PSU and Socket 939 motherboard offer much flexibility. You could easily use an Athlon 64 FX CPU and the PSU had no problems running our PCI-E GeForce 6800 GT graphics card.
When we ran our Media Benchmarks using our standard test kit, the SN25P performed admirably, scoring 1.31 overall. The system performed particularly well in the image editing test with a score of 1.44. The SN25P's results compare favourably to those of the Gigabyte GA-K8NXP-SLI, which was the last Socket 939 motherboard we tested using the same components. The Gigabyte achieved the same overall score, although its video editing score of 1.14 was slower than the SN25P's 1.19.
Unfortunately, we didn't get the results we were hoping for when we tried overclocking, with the SN25P managing a maximum effective FSB of 215MHz. This increased the 3500+ CPU's default speed of 2.2GHz to 2.36GHz. Although it wasn't a massive overclock, it achieved a much improved score of 1.38 overall, which equates to a whole speed grade increase and put the 3500+'s performance almost on a par with that of a 3800+. Overclocking also provided more of a performance increase than it did with the Gigabyte motherboard, proving that an nForce 4 SFF can easily keep pace with its full-sized rivals.
CONCLUSION
The SN25P has the ability to perform as well as an equivalent desktop system, which makes it a prime candidate for a compact workstation or gaming machine. The system's Socket 939 motherboard and PCI-E bus are standards at the beginning of their life cycle, so it's also a fast system that will be upgradable for some time to come.
Most importantly, it offers this performance and upgradability without taking up precious desk space. The SN25P is much better than recent Pentium 4 XPCs and has a great motherboard. The only drawback is that, filled with such cutting-edge components, it's very expensive.
