Shuttle SD31P Notes

After spending a week with my new Shuttle SD31P, I thought I’d offer up a few comments in my Dan’s Data-inspired verbose style! On the hardware itself, mostly. I’ll look at software and performance in a later post. Basically, Shuttle has delivered on it’s goal of packing an awful lot of computing power into a small, cool, and quiet form factor. It’s a remarkable feat, and the SD31P is probably the best “no compromise” SFF PC you can buy if you want to run a fast Intel CPU. If you prefer AMD’s Athlon64 I’m willing to bet the SD31P’s sister, the SN26P (where does Shuttle get these names from?), is a top-of-heap machine as well. Now, back to the Intel 945G based SD31P mini review.

SD31P highlights:

• Be careful with DDR2 memory timings - anything but 4-4-4-12 might not work.
• You can put a 6600GT with a Zalman VF700 GPU cooler in there with the VF700 at 5V and the SD31P system fan at its lowest speed.
• You can add a stinky fast (and hot) 3+GHz 600 series P4 and a fast video card and still have a quiet system!

And now, on with the verbosity:

Putting it together. Neat, tidy, and well thought out is take home message. All the metal edges are rounded, so you don’t get cut up. The cables are all cut to exactly the right length and expertly routed out of the way. You really don’t need tools, even the DVD writer and hard drive go in on rails that don’t require screws! The iCE heat-pipe CPU cooler installs easily and is well explained and diagramed in the manual. The machine goes together brilliantly and effortlessly. Much less fiddling, and much tighter tolerances than my previous Soltek QBiC. Design wise, the SD31P is just a beautiful little machine. I can’t really imagine how they’d improve given the size constraints.

Memory timings - oh my! This was my first spin around the block with DDR2 memory, and I have to say it reminded me a lot of the late 90s. I’d heard through the grapevine that DDR2 was some picky stuff and that I should stick with “a quality brand - skip the generic”. So I opted for OCZ’s Value Series PC2-4200 1GB 2×512MB DDR2-533 kit. At CAN$113 it’s certainly a good deal.

The Shuttle manual said I have to stick with CL4 timings on the memory, and the OCZ stuff comes as a hand-tested, dual-channel certified, lifetime warrantied CL4 kit. Should be no troubles, right? Wrong. When I put the memory in and powered the box up, I knew right away something was wrong. The Shuttle XPC logo had lots of horizontal bands of corrupted video crap through it. I checked that memory was in fact seated properly and double checked the iCE heatsink was a-ok. Everything looked good. Tried again, same thing. Random corruption of the startup logo. Go to the BIOS and everything looks a-ok though. No corruption. Boot a XP install CD, the blue screen portion of the install goes fine, hit the reboot and the kernel panics. Try a Linux boot CD, kernel panic before it finished booting the kernel. Hmmrph. So I venture into the BIOS and poke at every option in there, and notice that memory timings from the SPD are wrong! The Shuttle is trying to run the memory at 4-4-4-4! Aha! So I select manual config and set the tRAS at 8 and voila no video corruption and I get XP installed. First thing I do is check Shuttle’s site for a BIOS update, find there is one, apply it, and reboot. Video corruption. Gah! I go in, load the “optimized settings” to put everything back to defaults and reboot again. Still crap. When I check the memory settings I see that with the new BIOS, the SPD is actually now being read correctly and it’s picked 4-4-4-8, but I’m still hooped. So I do some research and find out that most, if not all, of the “value ram” sticks from Samsung and Kingston and Crucial are set 4-4-4-12 timings. I manually go and set my memory to 4-4-4-12 and I’m in business. I run memtest86 overnight, then prime95 while at work, no problems. Curious if I have bad RAM, I bring the sticks into work and slap into one of our IBM workstations that came with a DDR2 955X chipset. The IBM read the 4-4-4-8 timings off the SPD no problemo and showed no signs of duress under memtest86 or prime95.

So the lesson here is that the 945G chipset, or some peculiarity of Shuttle’s implementation, really wants to run the memory at 4-4-4-12 timings. So be it. From what I understand, the 8 in 4-4-4-8 (the tRAS) doesn’t actually mean the memory is any faster than if it was timed at 12. So there’s no performance loss, but it certainly makes you wonder why I had the problems at all…

Silence - almost. So just how quiet is the SD31P? I’m afraid it’s not silent. But it is damned quiet for an actively cooled (read “it has fans”) machine. Quiet enough that if you have anything else in your surroundings making noise, like air conditioning at the office, another computer, or even have the windows open, you might very well not hear the SD31P at all. Yip. That kinda quiet. There are three sets of fans in the system. A pair up in the top that supposedly cool the upper components like the optical and hard drives. A main system fan behind the power supply. And a pair of fans that push/pull air through the iCE heat-pipe CPU cooler. The two upper drive fans run at a fixed speed (~1000rpm) and are inaudible by most standards. The system fan’s speed can be controlled in the BIOS. By default it runs at “Ultra Low Speed”, and at that setting it’s audible, but it’s very, very quiet indeed. If you need more cooling, you can crank up the system fan to low, medium, or leaf-blower settings. At the low setting there’s definitely quite a bit more air being exchanged and while the noise level is obviously greater than at the lowest speed, it’s really not bad. That being said, even with a relatively hot video card (6600GT) inside my SD31P, I found the Ultra Low setting to provide more than adequate cooling. If you really pimped the system out with more drives and a mega-hot video card you’d probably pick the “Low” setting and still find the system very quiet. If you need the cooling of the medium or, heaven-forbid, the high speed setting than you probably shouldn’t be running a small form factor box to begin with.

The CPU fans are controlled automatically and ramp up and down depending on the temperature of the CPU. At their lowest speed setting, they’re very near inaudible and can’t be distinguished over the faint collective hum of the other fans. Once they speed up, however, the CPU fans are the noisiest in the system. How often they speed up will of course depend on the CPU you’ve got in the SD31P. I can say that the 3.2GHz 540J “Prescott” P4 I’ve currently got in there does spike in temperature as soon as it sees load, and the spike is enough to cause the CPU SmartFan to briefly rev up. During normal desktop activities, this is slightly annoying as you hear the fan rev up and down fairly frequently. It’s actually fairly astonishing how quickly the CPU temp spikes and the SmartFan speeds up once the CPU gets a bit busy. Equally astonishing is how quickly the iCE heat-pipe cooler brings that temp back down once the fans have picked up. Astonishing. But annoying. I borrowed a newer 3.0 GHz 630 Prescott and I didn’t notice the reving effect at all during desktop duty. The 600 series P4 Prescotts run a little cooler and in this case it seems it’s just enough to keep the SD31P’s SmartFan from needing to rev into its higher gear. The SD31P will take the new dual-core Pentium D processors, but I have trouble believing the CPU fans could keep those suckers cool at the lowest speed setting. Something to keep in mind when selecting a CPU.

With a full CPU load, no matter which series P4 you’re running, the SmartFan will run at the higher setting to keep the CPU temp under control. Once it’s ramped up I don’t think it’s that bad actually, and it’s a very effective heat pipe unit - even after a few hours of gaming my CPU stayed under 60C.

Video card options. Speaking of continuous CPU load and cooling challenges, lets talk video cards. The integrated video built into the SD31P motherboard isn’t total crap. Which is a nice change compared to the Intel Integrated Graphics solutions of the past. Image and text quality is excellent, and there’s enough acceleration there to handle XP menu shadows and fade effects and such with ease. In theory the built-in graphics are DirectX 9 capable, which means you should be able to at least load a modern 3D game or, say, Windows Vista. If you play games though, you’re gonna put something in that X16 PCI-Express slot! And this is where the SD31P really starts to seperate itself from the competition.

The photo hopefully makes two points: You can put a fairly big card in the SD31P, and the card’s “top” faces into the case. A lot of SFF boxes get the orientation of the card wrong and have top of the card facing the side of case cover. The QBiC is like this, and it sucks. With the top of the card right next to the cover air flow is severely compromised and you can forget any sort of aftermarket GPU cooling options, which is a major issue if you’re trying to keep your SFF quiet. But the SD31P gets it right and faces the card inwards. There’s actually enough room to put in a double slot card, assuming it’s not too long. You get an idea for all the room up in the top photo - you can see there’s little obstruction in front of the video card, and with all the CPU heat wicked out through the side the system fans can focus on keeping the chipset, RAM, and video card cool. The really great news is that not only can you put a fairly hefty video card in the SD31P, but chances are good that you’ll be able to keep it cool with the system fan set on the Ultra Low speed! The downside of this is that in all likelyhood this now means your video card’s fan is now by far the noisiest past of the system…

This was certainly the case when I added a Leadtek PX6600GT TDH to my system. Subjectively, the system was 3 times louder with the 6600GT installed. I had my fingers crossed that I’d have enough room to install a Zalman VF700 GPU cooler, and wouldn’t you know it, it *just* fits:

W00t! The drive cage just touches the VF700 fins, but with a little finesse the 6600GT is installed with a far superior cooling setup. Results? With the Zalman running at its lower speed setting (5V instead of 12V) and the system fan at the Ultra Low setting, the GPU runs at 42C in 2D mode! A great result, especially considering that the VF700 fan is barely audible over the existing SD31P fans.

Conclusion. The SD31P is a great machine. You can load it up with a fast processor, a big hard drive (or three), a fast graphics card, and plenty of RAM and it runs pretty quiet, keeps everything effectively cooled, and looks good to boot. Silent it is not, but it’s about as close as you can get with active cooling, producing no more noise than the PowerMac G5 in my echo-chamber basement test lab. And that’s saying something, since the G5 is considered a marvel in intelligent cooling design. No other SFF I’ve seen offers as much performance and flexibility in a machine you can be proud to have in plain sight up on your desk.