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Shuttle’s P-series line of small-form-factor systems represents a concerted effort to update the now-classic cube PC. The P-series is slightly larger than the company’s G4 line but offers more amenities, such as nearly tool-free installation, quieter operation, and more elegant cosmetics.

The SN25P pushes the Shuttle line forward, offering a small-form-factor Athlon 64 system that supports PCI Express. Shuttle is using nVidia’s nForce4 core logic, which brings PCI Express, Serial ATA, and Gigabit Ethernet to the socket 939 AMD platform. It sounds like a great recipe for a small high-performance gaming system.

But there is one wrinkle: The SN25P has no PCI slots. The system ships with one PCI Express x16 slot for graphics and one PCI Express x1 slot for other expansion. This is similar to the SB95P V2, which is Intel 925XE-based, but different from the Shuttle XPC SB81P, which offers PCI Express graphics but a standard PCI slot.

Gamers could use a PCI slot to add a PCI sound card, like Creative Labs’ Audigy 2 series. Digital media junkies might use a PCI slot to add a TV tuner card. We know of PCI Express TV tuner cards in the works, but Creative Labs doesn’t currently have PCI Express solutions on its roadmap, and neither does any other manufacturer of audio semiconductors.

Shuttle clearly realized this might be a problem. Rather than relying on the integrated audio built into the nForce4 chipset, Shuttle has integrated VIA Technology’s Envy24 audio chip onto the motherboard. It’s a reasonable compromise. The Envy24 offers high-resolution audio capabilities and hardware mixers, but lacks a DSP for acceleration of audio effects. As such, some games may experience a CPU hit if 3D audio is enabled.

So how does the Shuttle perform? We compared it to a similar desktop system running on a VIA K8T890 chipset. Can the tiny Shuttle keep up with the fully expandable ATX system? Continued…

Building a PC around a small-form-factor chassis can be challenging. The P-series chassis from Shuttle make assembly much easier, though you still need to do things in a certain order.

The SN25P offers the following features:

  • Support for AMD Athlon 64 Socket 939 CPUs
  • Two memory sockets for DDR400 (PC3200) memory modules
  • VIA Envy24 audio chip on the motherboard
  • One PCI x16 graphics slot and one PCI x1 expansion slot
  • Four USB ports on the back, and two in the front, under a flip-down door
  • Two six-pin, powered FireWire ports, one in front and one in back
  • Connections for 5.1 audio outputs, including two digital audio outputs (one coax, one optical). An optical digital audio input port on the back. Auxiliary headphone and microphone jacks underneath a flip-down door in the front.
  • A nifty CMOS reset button recessed into the back of the chassis. Should you get into trouble fooling around with the BIOS setup options, you can bail yourself out with this button. Since it’s recessed, you need a pen or other pointy device to press the button, so you probably won’t accidentally press it.
  • Gigabit Ethernet

No less than three fans grace the back of the chassis, though one is from the 350W power supply. In actual operation, the system is surprisingly quiet.

Installing Storage

Removing the cover requires unscrewing four thumbscrews and sliding the black aluminum cover off. Next up is to disassemble and remove the drive bay. The back of the bays have a pair of black plastic tabs that fasten the drive bay to the chassis. Lift them up and slide the bay backwards to remove it. The primary hard drive nestles into mount points on the bottom of the bay, and is locked down by side rails built into the bay itself. Shuttle provides adhesive rubber dampers that can minimize noise from drive vibration.

The black plastic tabs also serve as drive rails for the optical drive. Snap these out of the bay, snap them onto the optical bay and plug the whole affair back into the bay. We’ve now removed the drive bay, installed a hard drive and optical drive, and never used a single tool. Note that using a short optical drive, such as the Memorex 16x DVD burner we show here, greatly facilitates installing the drive bay back into the case. Continued…

We’re not quite ready to install the drive bays yet, though. Before we do that, we need to install the CPU and memory. (The PCI Express graphics card is best installed after the drive bays are in place.) Prior to installing the CPU, you need to remove the fan duct and heat sink. The fan duct latches onto a pair of small hooks in the motherboard. You can just unlatch them and lift it out.

The CPU cooler is a sideways-mounted version of Shuttle’s ICE heat pipe. It’s fastened to the motherboard via four thumbscrews. Unless your fingers are much smaller than mine, you’ll have to resort to a screwdriver to remove them.

Note that a pair of fans handles the CPU cooling. Both fans pull air away from the processor. One exhausts through the air duct, while the other pulls air from the vertically mounted fins that cool the heat pipes attached to the CPU heat sink.

Socket 939 is a traditional ZIF (zero insertion force) socket. You lift the lever up and drop in the CPU. You need to align a small triangle embossed on one corner the CPU package with a similar triangle embedded on the corner of the ZIF socket. Then it should just drop in. If it seems to require force, don’t push hard. Check your alignment first: Too much force risks bending some of the pins in the dense array underneath the CPU package.

Memory pops into the sockets. Ideally, you want a pair of identical modules, as the nForce4 chipset supports dual-channel DDR memory, which matches up nicely with the 128-bit-wide memory controller built into the Athlon 64 die.

Now it’s time to get the heat sink and cooling duct into place. Once you screw down the CPU cooler, it should nestle neatly against the right side cooling fan. You want to screw down the heat sink screws “finger tight”—don’t crank down too hard with the screwdriver. Continued…

Now it’s time to install the drive bay. That should slide easily back into the case. Shuttle has thoughtfully pre-installed one parallel ATA and two SATA cables, so all you need to do is attach them to the drives. Note that you may need to reroute the SATA cables, but the internal cable management system uses latches, rather than ties, to manage cable. So rerouting cables as needed is pretty easy.

The final step before you slide on the cover is to install the PCIe graphics card. The PCI Express slot is on the outside of the case, making installation easy. First, you need to remove the screws that keep the expansion slot covers in place. If you have a long card, like the GeForce 6800GT we used, then you’ll have to carefully work the back end of the card under the drive bay. You can install the card first if you like, but that makes rerouting cables a chore.

The system lacks one key component—a PCI Express graphics card power adapter. If you use a GeForce 6600GT, Radeon X700, or X800 XL, you won’t need an adapter. If you’re using a beefier graphics card, though, you’ll need to buy a 4-pin Molex to 6-pin PCIe power adapter. ATI sells these Molex adapters on its web site for about $10. Some white-box shops carry them as well.

Once the graphics card is in place, you screw down the slot covers and you’re ready to boot. (We have a superstition here that no new system will work properly if you install the cover prior to the first system boot).

After the system boots up, and you install your operating system of choice, you can finally slide on the front cover and you’re good to go. Continued…

We built up a PCI Express system using an ASUS A8V-E Deluxe motherboard, which uses the VIA K8T890 chipset—another PCI-E chipset for Socket 939. Here’s how the two systems were configured:

Component Full ATX System Shuttle SN25P
Processor Athlon 64 model 4000+ at 2.4GHz Athlon 64 model 4000+ at 2.4GHz
Motherboard and chipset ASUS A8V-E Deluxe, Via K8T890 Shuttle FN25
Memory 2 x 512MB Corsair XMS Pro at CAS 2-2-2-5 2 x 512MB Corsair XMS Pro at SDPD
Graphics Nvidia GeForce 6800GT PCI Express (66.93 drivers) Nvidia GeForce 6800GT PCIe (66.93 Drivers)
Hard drive Seagate Barracuda 7200.7 160GB, 7200RPM SATA Seagate Barracuda 7200.7 160GB SATA Drive
Optical drive ATAPI DVD-ROM Drive ATAPI DVD-ROM Drive
Audio Sound Blaster Audigy 2 Via Envy24
Operating system Windows XP Professional with SP2 Windows XP Professional with SP2

We ran a subset of the benchmark suite we used in our recent preview of the Intel Pentium 4 600 series. The list includes SYSmark 2004, 3ds max R6, LightWave 7.5, Windows Media Encoder 9, DivX 5.2.1, PCMark04, 3DMark05 and four CPU-intensive PC games.

We need to note one issue we ran into with the memory configuration. Our past experience with nVidia chipsets indicates that they have no problems running at CAS2-2-2-5 memory timings with low-latency memory. So we tried to manually set the XMS Pro memory to CAS-2-2-2-5, 2-2-2-6 and 2-3-3-6. Each time, the system would boot, but Windows XP would be corrupted and not respond properly. Finally, we set the system to SPD (auto timings) and everything ran fine, but the SPD settings are likely more conservative than any of our manual settings.

The hard drives were defragged prior to each major benchmark run. Also, we used the rundll32.exe advapi32.dll,ProcessIdleTasks command to execute and shut down tasks that would normally run during idle cycles.

We ran an extended suite of 32-bit benchmarks:

  • SYSmark 2004, patch 2, a general applications benchmark suite from BAPCo.
  • Content creation, including 3ds max R6, Windows Media Encoder 9, DivX 5.2.1 and LightWave 7.5.
  • Synthetic benchmarks: 3DMark05 Version 120 and PCMark04.
  • Game benchmarks: Doom3, Painkiller, Microsoft Flight Simulator 2004, and Unreal Tournament 2004. Except for Doom3, audio was enabled during game benchmarking. Continued…

First up are the results from SYSmark 2004. SYSmark simulates real-life workloads for both Internet Content Creation and Office Productivity. The content-creation portion uses apps like Photoshop, 3D Studio, Dreamweaver and others, while the office productivity tests use typical office apps, like PowerPoint, Word, and Excel.

The differences here are minor, but the SN25P does lead narrowly in both the Office Productivity and Internet Content Creation tests. It’s doubtful that the differences are meaningful, though. Continued…

PCMark04 consists of a series of synthetic benchmark suites, each designed to test individual subsystems, such as memory, processor, and hard drive. Note that the test autodetects the CPU and loads dynamic libraries for each function optimized for the processor under test. So an Athlon 64 would run code that’s tweaked to run best on its architecture, while a P4 running the same test would run different code optimized for that processor. As such, it’s an idealized view of performance. In the real world, application optimizations can vary widely.

The SN25P continues to lead by a slight margin. Note that the nForce4 chipset posts a modestly higher score in the memory tests, despite having to run at SPD. So the nForce4’s prefetcher seems fairly efficient. Continued…

Now we turn to performance using real applications. We’ll take a look at a pair of popular 3D modeling and rendering tools: 3ds max R6 and LightWave 7.5. 3ds max performs double duty here, as we run the SPEC APC 3D Studio test, which tests performance of 3ds max by running model creation, modification and rendering script. Note that we’re stuck with R6 for the moment, as the SPEC benchmark hasn’t been updated to work with the latest 3ds max release 7. We also perform several pure rendering tests with 3ds max:

The SN25P posts faintly better results in the 3ds max 6 tests, but slightly poorer results in LightWave 7.5, than the A8V-E. Continued…

We used Windows Media Encoder 9 and the latest 5.2.1 release of the DivX codec to perform our tests. We’ve shifted our WME tests to use the Windows Media 9 advance profile codec, which was included as part of Windows Media Player 10. The advanced profile adds more functionality for encoding WMV files, including denoise, interlaced, and progressive encoding options.

Again, we see very modest improvements in the test results with the Shuttle system compared to the A7V-E test bed. Continued…

We use four games, plus 3DMark05 to check out performance on games. The games include Doom 3, Painkiller (1.6.1 update), Flight Simulator 2004, and Unreal Tournament 2004. All make fairly heavy use of the processor and memory subsystem.

Here’s another 3DMark05 conundrum: The Shuttle system posts better scores in this test than it does in actual games, relative to the ASUS-based system. The difference was smallest in Doom 3, where the audio was disabled. The combination of more conservative memory timings and the Envy24 audio resulted in an ever-so-slight brake on the otherwise superb gaming performance of the Athlon 64 4000+. But we need to stress that the differences are really quite small. It’s also possible that a future BIOS update could enable greater stability with aggressive memory timings, which should close the gap. Continued…

Shuttle has another winner on its hands with the SN25P. But we do have a slight niggling doubt: Is the system perhaps too forward looking? On the one hand, we think that PCI Express is an exciting technology, and certainly a big improvement over 32-bit PCI. But it would have been more practical for today’s user if the system offered an “old-fashioned” PCI slot.

Still, the overall performance of the SN25P is nothing to sneeze at. With the exception of gaming, the Shuttle generally outperformed a VIA K8T890-based ASUS motherboard. Even the differences in gaming performance were pretty minor in our eyes. So if you don’t mind forgoing the use of older PCI cards and are instead looking forward to superb performance an a future rich in PCI Express expansion cards, then the SN25P is a worthy contender.

Product : Shuttle XPC SN25P
Company: Shuttle Computer
Price: TBD
Pros: nForce4 chipset; socket 939 support; Envy24 high resolution audio; PCI Express x16 graphics; 350W power supply; relatively quiet; easy assembly.
Cons: No PCI slots; Envy24 audio CPU utilization relatively high; no PCI Express 6-pin graphics power connector
Summary: Shuttle updates the P-series, offering support for socket 939 Athlon 64 CPUs. The lack of a PCI slot may shut out some buyers, but they’d be missing out on a great little system that delivers excellent performance.