The dearth of new small form factor barebones designs nicely sets the stage for a Shuttle comeback, and although the company may never match the frenetic pace of barebones development it achieved a few years ago, it does have a couple of all-new small form factor systems for the enthusiast market. First out of the gate is the XPC SN27P2, a tweaked successor to Shuttle’s P series chassis with Socket AM2, an nForce 570 Ultra chipset, and a beefy 400W power supply under the hood.
Can the SN27P2 recapture Shuttle’s former glory and make the small form factor world exciting again? Read on to find out.
Shuttle has made numerous changes to its XPC design with the SN27P2, some of which are even apparent with a cursory glace at the system’s spec sheet.
|CPU support||Socket AM2-based Athlon 64 processors|
|North bridge||nForce 570 Ultra MCP|
1 PCI Express x16
|Memory||4 240-pin DIMM sockets
Maximum of 8 GB of DDR2-400/533/667/800 SDRAM
|Storage I/O||Floppy disk
1 channels ATA/133
4 channels Serial ATA with RAID 0, 1, 0+1, 5 support
|Audio||8-channel HD audio via nForce 570 and Realtek ALC882 codec|
6 USB 2.0 (rear)
2 USB 2.0 (front)
1 1394a Firewire via VIA VT6307 (rear)
1 1394a Firewire via VIA VT6307 (front)
1 RJ45 10/100/1000
1 eSATA 1 analog front out
1 analog bass/center out
1 analog rear out
1 analog line in
1 analog mic in
1 coaxial digital S/PDIF output
1 TOS-Link digital S/PDIF output
1 TOS-Link digital S/PDIF input
|Bus speeds||HT: 200-300MHz in 1MHz increments
DRAM: 400, 533, 667, 800MHz
|Bus multipliers||LDT: 1x-5x|
|Voltages||CPU: auto, 0.8-1.525V in 0.025V increments
DDR: auto, 1.9-2.0V in 0.05V increments
Chipset: auto, 1.55-1.6V in 0.05V increments
|Monitoring||Voltage, fan status, and temperature monitoring|
|Fan speed control||CPU, system|
Space constraints usually limit small form factor systems to only two DIMM slots, but Shuttle manages to squeeze four into the SN27P2. These DDR2 memory slots nicely complement the system’s AM2 socket, which supports AMD’s latest and greatest Athlon 64 processors. AMD’s new Energy Efficient Athlons seem particularly well suited for Shuttle cubes, and there’s even an “Athlon 64 X2 3800+ Energy Efficient Small Form Factor” with a 35W designed specifically with small enclosures in mind.
Speaking of new chips, the SN27P2 includes NVIDIA’s nForce 570 Ultra core logic. The nForce 570 Ultra is based on the same basic technology as the nForce 590 SLI, although a few of that high-end chipset’s features don’t make the cut for the Ultra. SLI isn’t supported, for examplenot that it’s needed in a small form factor system with only one PCI Express x16 slot. LinkBoost doesn’t make the cut, either, although without SLI or a chipset interconnect, there’s no need for it.
The nForce 570 Ultra doesn’t have a chipset interconnect because it lacks traditional north and south bridge components; like nForce designs of old, the 570 Ultra is a single-chip design. NVIDIA still manages to cram plenty of features onto the single chip, including 20 PCI Express lanes, six Serial ATA RAID ports, dual hardware-accelerated Gigabit Ethernet controllers, and support for Intel’s High Definition Audio standard.
Presumably due to space constraints, the SN27P2 only implements four of the chipset’s Serial ATA RAID ports. That’s to be expected in a small form factor system with limited capacity for internal hard drives. However, it would have been nice to see Shuttle take advantage of both of the 570 Ultra’s GigE controllersonly one is implemented in the SN27P2.
The SN27P2 uses an updated version of Shuttle’s P series chassis, but the cube’s basic dimensions are largely unchanged. The chassis itself measures 325 mm long, 220 mm wide, and 210 mm tall, so it’s still slightly larger than Shuttle’s G-series designs, but much smaller than even Micro ATX enclosures.
Overall, the SN27P2’s appearance is sleek and stylish. The all-black aesthetic is hardly original, but at least it goes with everything. Contrasting textures and materials give the SN27P2’s face a little bit of flair, too. The glossy plastic does tend to attract fingerprints, though, especially around the eject and power buttons.
As usual, Shuttle does a good job of stealthing the system’s external drive bays. External 5.25″ and 3.5″ bays are neatly hidden behind hinged doors, and the 5.25″ bay’s remote eject button is flexible enough to work with a wide range of optical drives.
Note that Shuttle isn’t including an integrated card reader this time around. Previous P-series designs have included memory card slots up front. Fortunately, the SN27P2’s external 3.5″ drive bay can easily accommodate a card reader/floppy combo drive.
Shuttle equips the SN27P2 with a pretty standard array of ports along the bottom of the system’s face. These include analog audio, USB, and Firewire jacks, all of which are neatly hidden behind another hinged door.
Moving to the rear of the system, we can see that Shuttle gives the SN27P2’s internals plenty of ventilation. Holes perforate much of the system’s external skin, and there’s even additional venting on the underside of the chassis.
Around the back, the SN27P2 has even more ventilation for its hard drive and power supply cooling fans. There’s also a generous array of expansion ports, although traditionalists will note that the system lacks serial, parallel, and PS/2 keyboard and mouse ports. Abit tried a similar legacy-free port cluster years ago, and the idea never really caught on. It might this time around, though. USB keyboards and mice are plentiful these days, and even USB KVM switches aren’t hard to find.
Still, I’m sure the lack of PS/2 ports will irk at least a few stubborn old codgers. While they bemoan the lack of legacy ports, the rest of us can enjoy the port cluster’s more timely delights, including its eSATA jack and digital S/PDIF input and output ports. Shuttle even provides S/PDIF output in coaxial and TOS-Link flavors. An external CMOS reset button is also included so you don’t have to dig around in the case if your latest overclocking attempt fails.
Removing the SN27P2’s outer skin is a simple affair, but disassembly isn’t complete until we remove the system’s drive cages.
This is a somewhat more involved process than in older P-series boxes, which included tool-free plastic hard drive cages. Shuttle says the cages would occasionally break when units were shipped with hard drives installedsomething it no doubt learned from its foray into system buildingso the SN27P2 reverts back to metal cages held in place by traditional screws.
The P series’ tool-free design will undoubtedly be missed, but it takes less than a minute to unscrew and pop out the SN27P2’s three drive cages, so there’s hardly cause for revolt. We’d prefer a more secure hard drive mounting system to one that saved us a few seconds, anyway.
It also helps that the system’s expansion slots are accessible even with the drive cages in place. Shuttle puts the PCI Express x16 slot on the outer edge of the motherboard, so it’s possible to install double-wide graphics cards like NVIDIA’s GeForce 7900 GTX. You lose access to the PCI slot, of course, but Shuttle says the SN27P2’s 400W power supply has enough oomph to handle the demands of high-end graphics cards.
Installing a double-wide graphics card into the cramped chassis takes a little effort, and Shuttle’s done a good job of ensuring that you don’t scratch up the board in the process. A protective layer of plastic covers the area directly to the right of the PCI Express x16 slot to prevent a graphics card’s PCI back plate from making direct contact with the motherboard or other surface-mounted components. Little details like this clearly illustrate that Shuttle knows its way around smaller form factors.
Just beyond the PCI slot we find the SN27P2’s chipset and Serial ATA ports. There are only three SATA ports on the board, with the fourth routed to the rear port cluster’s eSATA port. Note that Shuttle also relies on active chipset cooling. The single-chip nForce 570 Ultra puts out too much heat to be adequately cooled by a passive heatsink in the SN27P2’s toasty internals.
On the left side of the system, users have access to the SN27P2’s four DIMM slots and its IDE and floppy ports. The CPU socket’s over to the right, hiding under the SN27P2’s custom cooler.
Cooling a processor within the cramped confines of a small form factor system isn’t easy, but Shuttle’s XPC designs have always done an exceptional job without making too much noise. The SN27P2’s processor cooler is essentially unchanged from previous P-series designs; a smaller fan (to the left in the picture) draws cool outside air into the system and blows it over a series of radiator fins. A larger diameter fan works the opposite end of the cooler (to the right in the picture) and exhausts warm air from the system.
The SN27P2’s processor cooler relies on variable-speed fans, so the noise levels it generates depend on the heat output of your processor. In testing, we found the system to be reasonably quiet with an Athlon 64 X2 5000+ and GeForce 7900 GTX installed.
In addition to those found in the processor cooler, a pair of smaller fans sits at the rear of the case to provide cooling for the system’s hard drives. Again, these are variable-speed units, and rather quiet ones at that.
From this angle, we can also see the SN27P2’s power supply. This Silent X model boasts a 400-watt rating and includes a six-pin power connector for PCI Express graphics cards. It also sports power factor correction, a feature that’s actually required by the European Union.
Tweaking and overclocking options are probably the last thing Shuttle wants in a BIOS for its complete systems division, but they’re essential for enthusiast-oriented barebones systems. Fortunately, the SN27P2’s BIOS has just enough options to keep most enthusiasts happy.
HyperTransport clock speeds are available between 200 and 300MHz, which should be more than enough for most. However, the BIOS’s core voltage options only go up to 1.525V. That’s not nearly enough for more extreme overclocking, although in a system with such limited airflow, you probably don’t want to be turning voltages up too much.
A decent array of memory timing options also makes it into the SN27P2’s BIOS, though the list isn’t as extensive as what’s available in other Athlon 64 motherboard BIOSes. Still, the big fourCAS latency, RAS-to-CAS delay, RAS precharge, and active-to-precharge delayall make an appearance. Control over the DRAM command rate is currently only available in a beta BIOS.
Fan speed control should be an integral part of any small form factor system’s BIOS, and the SN27P2 serves up 10 fan speed profiles. Users can lock the fan to a specific speed or have fan speeds ramp and throttle to maintain one of six given CPU temperature. Additional fan speed control is available through Shuttle’s XPC Tools software, which we’ll discuss in a moment.
Before we dive into XPC Tools, it’s worth noting that the SN27P2’s BIOS also lets users adjust the brightness of the system’s blue power LED. Many a home theater PC user has cursed the piercing brightness of blue LEDs in the dark, so it’s nice to be able to tone down the volume a little.
If you don’t want to poke around in the BIOS to adjust fan speeds and other system variables, the SN27P2 also supports Shuttle’s own XPC Tools Windows utility. XPC Tools has been in development for what seems like forever, and the app’s current incarnation is pretty polished.
XPC Tools can be used to monitor system variables, such as fan speeds, temperatures, and voltages.
Overclocking options are also included, although control over the system’s CPU multiplier is not. If you’re not comfortable changing the CPU multiplier in the BIOS, you probably shouldn’t be overclocking, anyway.
Users are also given more extensive control over the system’s variable-speed fans. Minimum “Smart Fan” speeds can be defined in addition to the threshold temperature that triggers an increase in fan speeds.
XPC Tools can manage multiple profiles, so it’s easy to define a few for lower noise levels or faster performance. The SN27P2 also offers support for NVIDIA’s latest nTune system utility, which unlocks a considerably more extensive array of tweaking options.
NVIDIA’s utility provides access to a wide range of memory timing options. The app also supports voltage and fan speed control, but Shuttle hasn’t included the BIOS hooks necessary for those features to work. XPC Tools’ fan speed control options are better than those available in nTune, anyway.
nTune includes a monitoring utility, but the SN27P2’s BIOS doesn’t correctly report voltages to it. Fortunately, it’s still possible to use nTune’s custom rules control panel, which allows the system to switch automatically between nTune profiles according to user-defined conditions.
We’re comparing the SN27P2’s performance to that of a couple of full-size Socket AM2 motherboards from Asus and Foxconn.
All tests were run at least twice, and their results were averaged, using the following test systems.
|Processor||Athlon 64 X2 5000+ 2.6GHz|
|System bus||HyperTransport 16-bit/1GHz|
|Motherboard||Asus M2N32-SLI Deluxe Wireless Edition||Foxconn C51XEM2AA-8EKRS2H||Shuttle XPC SN27P2|
|North bridge||nForce 590 SLI SPP||nForce 590 SLI SPP||nForce 570 Ultra|
|South bridge||nForce 590 SLI MCP||nForce 590 SLI MCP|
|Chipset drivers||ForceWare 9.35||ForceWare 9.35||ForceWare 9.16|
|Memory size||2GB (2 DIMMs)||2GB (2 DIMMs)||2GB (2 DIMMs)|
|Memory type||CorsairTWIN2X2048-6400PRO DDR2 SDRAM at 800MHz|
|CAS latency (CL)||5||5||5|
|RAS to CAS delay (tRCD)||5||5||5|
|RAS precharge (tRP)||5||5||5|
|Cycle time (tRAS)||12||12||12|
|Audio codec||Integrated nForce 590 SLI MCP/AD1988B with 184.108.40.206 drivers||Integrated nForce 590 SLI/ALC882D with Realtek HD 1.39 drivers||Integrated nForce 570 Ultra/ALC882 with Realtek HD 1.39 drivers|
|Graphics||GeForce 7900 GTX 512MB PCI-E with ForceWare 91.31 drivers|
|Hard drive||Western Digital Caviar RE2 400GB|
|OS||Windows XP Professional|
|OS updates||Service Pack 2|
Thanks to Corsair for providing us with memory for our testing. 2GB of RAM seems to be the new standard for most folks, and Corsair hooked us up with some of its 1GB DIMMs for testing.
Due to the peculiarities of the Athlon 64’s on-die memory controller, our systems are actually running their memory at 742MHz. The Athlon 64 doesn’t have enough memory dividers to hit 800MHz exactly at every speed grade, and the closest the 5000+ comes without going over is 742MHz.
Also, with the exception of our XPC SN27P2, all of our test systems were powered by OCZ GameXStream 700W power supply units. Thanks to OCZ for providing these units for our use in testing.
We used the following versions of our test applications:
- SiSoft Sandra Standard 2005 SR3
- WorldBench 5.0
- TCD Labs HD Tach v3.01
- Futuremark 3DMark06 Build 1.02
- Far Cry v1.3
- Splinter Cell Chaos Theory v1.05
- RightMark Audio Analyzer 5.5
- RightMark 3D Sound 2.2
- Cinebench 2003
- Sphinx 3.3
- trq4demo1 demo
- F.E.A.R. 1.04
The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests. Most of the 3D gaming tests used the Medium detail image quality settings, with the exception that the resolution was set to 640×480 in 32-bit color.
All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.
The SN27P2’s memory performance is largely consistent with our other Socket AM2 systems, although its latency is a smidge higher. Nearly identical scores are no surprise because the Athlon 64’s memory controller is located on the processor die and shared by all our platforms.
Athlon 64 platforms don’t always respond well to four-DIMM configurations, so we slapped a couple of extra memory modules into each system and re-ran our memory bandwidth and latency tests. None were happy running four DIMMs with a 1T command rate, so we had to drop back to 2T to regain stability. We’ve yet to encounter an Athlon 64 system that will run four DIMMs at a 1T command rate.
Memory latency evens out as we switch to four DIMMs, and bandwidth is close across the board.
The SN27P2 pulls off an unexpected win in WorldBench, beating its closest competitor by a full three points. A number of WorldBench’s individual tests show a noticeable advantage for the XPC, including Photoshop, 3D Studio Max, and VideoWave Movie Creator.
Not even one frame per second separates the SN27P2 from our full-size Athlon 64 platforms in most of our first round of gaming tests.
Our first round of gaming tests was conducted with more modest in-game detail levels and display resolutions, but we’ve cranked things up for a second round. These tests use high resolutions, high detail levels, and anisotropic filtering and antialiasing. We’ve also tested the Asus and Foxconn boards with a pair of 7900 GTXs in SLI. The SN27P2 doesn’t support SLI, so it will have to make do with a single card.
Although it remains competitive with a single card, the XPC misses out on the opportunity for much higher frame rates through the addition of a second graphics card in SLI. Even so, average frame rates between 50 and 76 frames per second at 1600×1200 with 4X antialiasing and 16X aniso are quite good.
Cinebench scores are close…
Sphinx speech recognition
And Sphinx is essentially a tie.
The Foxconn and Shuttle motherboards both use Realtek’s high definition audio codec, so it’s no surprise to see the two score similarly in RightMark’s 3D audio tests. However, the Asus M2N32-SLI, with its Analog Devices codec, has quite an advantage in this test.
We used an M-Audio Revolution 7.1 sound card for recording in RightMark’s audio quality tests. Analog output ports were used on all systems. To keep things simple, I’ve translated RightMark’s word-based quality scale to numbers. Higher scores reflect better audio quality, and the scale tops out at 6, which corresponds to an “Excellent” rating in RightMark.
Since the SN27P2 has analog audio jacks in the front and rear, we tested both. The rear ports score better in RightMark Audio Analyzer, which isn’t terribly surprising considering that signals have to traverse the length of the system to get to the front ports.
Against its competition from Asus and Foxconn, the SN27P2 does rather well. Shuttle’s XPC takes top honors in the noise level and dynamic range tests, and only falls to the M2N32-SLI in the frequency response test.
ATA performance was tested with a Seagate Barracuda 7200.7 ATA/133 hard drive using HD Tach 3.01’s 8MB zone setting.
The SN27P2’s ATA performance is all but identical to that of our other Athlon 64 systems.
Moving to Serial ATA, we tested performance with a Western Digital Raptor WD360GD SATA hard drive. Again, we used HD Tach 3.01’s 8MB zone test.
As it did in our ATA performance tests, the XPC has no problem keeping up with the competition in our Serial ATA tests.
Our USB transfer speed tests were conducted with a USB 2.0/Firewire external hard drive enclosure connected to a 7200RPM Seagate Barracuda 7200.7 hard drive. We tested with HD Tach 3.01’s 8MB zone setting.
Write speeds are a little slower on the SN27P2 than the other Athlon 64 systems, but not by much. At least CPU utilization during USB transfers is consistent.
Our Firewire transfer speed tests were conducted with the same external enclosure and hard drive as our USB transfer speed tests. It’s just a 1394a Firewire enclosure, so it won’t benefit from the higher speeds supported by the C51XEM2AA’s 1394b Firewire chip.
Windows XP doesn’t fully support 1394b Firewire, anyway. In fact, with Service Pack 2, XP throttles the performance of 1394b Firewire devices to below 1394a speeds. This issue is detailed in this Microsoft support document, which provides a patch for SP2 users. We’ve tested both of the C51XEM2AA’s Firewire ports with and without the patch installed.
Firewire performance isn’t a problem for the SN27P2, which is only a hair slower than the M2N32-SLI.
We evaluated Ethernet performance using the NTttcp tool from Microsoft’s Windows DDK. The docs say this program “provides the customer with a multi-threaded, asynchronous performance benchmark for measuring achievable data transfer rate.”
We used the following command line options on the server machine:
ntttcps -m 4,0,192.168.1.25 -a
..and the same basic thing on each of our test systems acting as clients:
ntttcpr -m 4,0,192.168.1.25 -a
Our server was a Windows XP Pro system based on Asus’ P5WD2 Premium motherboard with a Pentium 4 3.4GHz Extreme Edition (800MHz front-side bus, Hyper-Threading enabled) and PCI Express-attached Gigabit Ethernet. A crossover CAT6 cable was used to connect the server to each system. The boards were tested with jumbo frames disabled.
There’s little variance in Gigabit Ethernet throughput, but the XPC has a slight advantage over our nForce 590 SLI platforms when we look at CPU utilization. NVIDIA actually has individual ForceWare driver packages for the nForce 570 Ultra and 590 SLI chipsets, and each uses a slightly different version of the company’s networking driver. The 570 Ultra package uses the 55.21 Ethernet driver, while the 590 SLI package features a newer 60.15 networking driver. Differences between the two versions are likely responsible for the 2% advantage the SN27P2 enjoys in the ntttcp CPU utilization test.
We measured system power consumption, sans monitor and speakers, at the wall outlet using a Watts Up power meter. Power consumption was measured at idle and under a load consisting of a multi-threaded Cinebench 2003 render running in parallel with the “rthdribl” high dynamic range lighting demo.
Our Asus and Foxconn motherboards were tested with an OCZ GameXStream 700W power supply, while the SN27P2 used its own integrated Silent X 400W unit.
Our SN27P2 test system consumes less power at idle and under load than either full-size ATX platform, but that’s not entirely unexpected. After all, the Asus and Foxconn boards both sport two-chip core logic chipsets and extra onboard peripherals. They were also tested with a beefier power supply rather than Shuttle’s proprietary unit, which doesn’t work in standard ATX motherboards.
The Athlon 64’s memory divider mechanism makes memory overclocking complicated at best and infuriating at worst. To avoid driving ourselves to the brink of frustrated insanity, we’ve limited the bulk of our overclocking tests to seeking out the highest stable HyperTransport clock for each board.
For our HyperTransport overclocking tests, we backed off on our CPU, memory, and HyperTransport processor link multipliers to remove them as potential problems. Next, we started turning up the HyperTransport clock, testing for stability along the way.
Unfortunately, we didn’t get very far. Our SN27P2 wouldn’t post with a HyperTransport clock above 225MHz, and no amount of extra voltage or positive reinforcement could coax the board to boot at 230MHz. 225MHz was no problem, though, and the SN27P2 looped plenty of runs of Prime95 and a 3D graphics demo at that speed.
Interestingly enough, we’ve seen quite a few motherboards peter out at 225MHz. With some, the lack of a proper PCI Express bus lock has been the culprit, but it’s unclear whether that’s holding the SN27P2 back.
As always, keep in mind that overclocking success is never guaranteed. Results can depend as much on the mix of system components as they can on the characteristics of individual samples, and your mileage may vary.
I don’t know whether Shuttle created the SN27P2 because it saw an opportunity to reinvigorate its barebones systems business or it just needed an updated model for Socket AM2. Either way, the SN27P2 has proven itself to be a fine barebones system for PC enthusiasts.
In a sense, the SN27P2 is vintage Shuttle. The system was released soon after AMD’s Socket AM2 processors became available, and its nForce 570 Ultra chipset comes from a cutting-edge core logic family. Perhaps more importantly, the SN27P2 is filled with thoughtful little features that only a small form factor veteran like Shuttle would recognize as essential.
But it isn’t perfect, perhaps because Shuttle hasn’t been paying as much attention to the enthusiast market. The fact that the SN27P2 doesn’t implement the nForce 570 Ultra’s second Gigabit Ethernet controller is curious to say the least. There’s no good reason to leave a feature like that sitting on the table, especially given the chipset’s ability to team its Gigabit Ethernet connections.
We generally don’t criticize products for a lack of overclocking potential, but I’m going to make an exception for the SN27P2. A 25MHz HyperTransport overclock is pretty weak, and it won’t allow you to fully utilize fancy DDR2-1066 memory. Those looking to exploit the “free” overclocking potential available in low-end processors like the Athlon 64 3800+ won’t be able to do much with an SN27P2, either. We don’t expect extreme overclocking from a small form factor system; we just expect better than a 25MHz HyperTransport overclock.
That said, if you have no inclination towards overclocking and no need for a second Gigabit Ethernet controller, the SN27P2 is about as perfect as small form factor systems come these days.