Over the past little while, Corsair seems to have developed a taste for small form factors. The company introduced its first microATX enclosure, the Obsidian Series 350D, back in August. That chassis wasn’t tiny by any means—indeed, it was somewhat large by microATX standards—but it was as small as Corsair had gone.
Well, now, Corsair has gone even smaller.
Today, the company takes the wraps off the Obsidian Series 250D, its first case designed around the diminutive Mini-ITX form factor. At 11.4″ x 10.9″ x 13.8″, this is officially Corsair’s tiniest case by far. And at $89, it’s also one of the company’s most inexpensive enclosures.
Don’t let the small dimensions and (relatively) low price fool you. The Obsidian Series 250D retains much of Corsair’s trademark tool-less goodness, and it blends sobriety and elegance in much the same way as Corsair’s other offerings. It’s no accident that the 250D is part of the Obsidian Series, which comprises some of Corsair’s finest high-end enclosures.
Seen from the outside, the Obsidian Series 250D looks an awful lot like the Obsidian Series 350D and its full-sized cousin, the Obsidian Series 750D. The 250D’s brushed-metal front panel is similar, and it has the same sort of groove that runs all the way around the edge. (That groove is, of course, a vent for the front intake fan. More on that in a moment.) The feet and the side vents follow similar styling.
Even from the back, the 250D is classic Corsair. There’s a small window at the top, so you can peer down at your motherboard; and there are vents on both sides, left and right. In a case this tiny, cooling a full-wattage processor and graphics card can be a challenge. More vents allow additional airflow through the chassis.
Corsair doesn’t skimp on thumb screws, either. We’ll crack open the case for a full look at the internals very soon, but for now, it’s already obvious that the top, left, and right panels are all easily removable. The same goes for the cover that sits over the 2.5″ and 3.5″ storage bays—and for the bracket that’s over the power supply compartment. No screwdrivers required there.
Speaking of those internals, here’s a quick run-down of the Obsidian Series 250D’s specs, including how much gear it can carry:
|Corsair Obsidian Series 250D|
|Dimensions (H x W x D)||11.4″ x 10.9″ x 13.8″|
|3.5″ drive bays||2|
|2.5″ drive bays||2|
|5.25″ drive bays||1|
|Included Fans||1x 140-mm front intake
1x 120-mm side exhaust
|Front panel I/O||2x USB 3.0
2x USB 2.0
|Max. graphics card length||11.8″|
|Max. CPU cooler height||3.7″|
|Gap behind motherboard||N/A|
The 250D isn’t as small as certain other Mini-ITX cases, like Silverstone’s SG07. But thanks to its larger dimensions, the 250D has room for a wealth of hardware: a graphics card up to 11.8″ long (meaning anything up to and including thousand-dollar behemoths), two hard drives, two SSDs, one 5.25″ optical drive, one full-sized ATX power supply, up to five fans, and a liquid-cooling radiator up to 240-mm long.
Out of the box, the 250D comes with one 140-mm fan at the front and another 120-mm spinner pinned to the right side, next to the CPU socket. Both fans are AF-series models of Corsair’s own design. It’s possible to mount an additional 120-mm fan on the side and two 80-mm ones at the back, as well.
Conventional CPU cooling is a little more limited. The 250D will only fit CPU heatsinks up to 3.7″ tall. As we’re about to discover, that limitation can be exceeded in a build without a 5.25″ optical drive—but not by very much. The big, tower-style heatsinks common in desktop rigs just won’t fit inside the 250D.
A closer look
Just like on the 350D and 750D, pushing on the top two corners of the front panel unlatches it from the rest of the case. Access is then granted to the (removable) front dust filter and to the screws that hold the intake fan in place.
The picture above shows the front panel hanging from its hinge, but don’t worry: that panel can come off. If it didn’t, getting to those fan screws would be needlessly difficult.
Here’s a look at the left side of the 250D with the top and side panels removed. See that black box with the vertical stripes? The motherboard is supposed to lay flat on top of it, and the power supply, hard drives, and SSDs are meant to go underneath. The area between that box and the front intake fan is reserved for cable routing. Mercifully, Corsair protects the fan blades from stray cables with a removable grill.
Here’s the view from the right. We can’t see much of note from this angle, except perhaps for the two side 120-mm fan mounts (one of which is populated by a Corsair AF120L) and the sides of the 2.5″ and 3.5″ drive bays. Those bays aren’t populated from the inside, however.
They’re populated from the back.
The 2.5″ and 3.5″ drive trays face the rear of the case, and they’re hidden behind a small grill, itself held in place with thumbscrews. There are two trays for each drive size. The 3.5″ trays are similar to those in other Corsair enclosures: they have a flexible plastic frame with steel studs designed to mate with a drive’s screw holes. The 2.5″ trays follow the same basic design—which, incidentally, is a first among the Corsair cases I’ve seen. The 350D and 750D both use other kinds of brackets and contraptions to fit 2.5″ drives.
Now, the 250D isn’t really limited to two SSDs. Its two 3.5″ trays both have 2.5″ mounting holes in their bellies, so if you don’t mind sacrificing mechanical storage, it’s possible to have four SSDs in all. You’ll just have to screw the last two into place manually.
A closer look—continued
Let’s take a last look around the Obsidian Series 250D before we fill ‘er up with components.
Yep. Those drive trays are pretty easy to get to.
Next to them lies the PSU compartment, which features a removable bracket that mounts onto the back of the power supply. (The bracket is then fastened to the back of the case via thumb screws.) Thanks to this bracket, the PSU can be inserted from the outside with very little pain. Most ATX enclosures require the PSU to be inserted from within the chassis, but the 250D isn’t roomy enough for that—and even if it were, the procedure would be more awkward. The only downside of inserting the PSU from the outside is that, before the unit can go in, the power cables must be pushed through the PSU compartment and into the main chassis.
Above the storage and PSU compartments are the gap for the motherboard’s I/O cluster and the expansion slot covers. Note that those are flush with the back of the case. On conventional ATX enclosures, the motherboard is recessed about a half inch from the rear panel, and the I/O cluster and expansion area site inside of a little nook. Not so on the 250D. This nook-less arrangement saves a little space inside the case, but it means expansion card brackets protrude out the back and must be screwed down outside the enclosure. (Note the little ledge at the top right of the picture.)
Finally, the 250D’s rear panel plays host to two 80-mm fan mounts. Corsair doesn’t include 80-mm fans in the box, but one would expect the stock 140-mm and 120-mm spinners to do a good job without any backup.
The 5.25″ bay is bolted down to the frame with four screws. Those can be removed to excise the bay. Doing so frees up some space for a larger CPU heatsink, and it’s also handy during the assembly process, when one generally needs as much room to maneuver as possible.
The Obsidian Series 250D has dust filters, naturally. We already saw the front filter on the previous page, but there are three additional ones. The left and right side panels both have their own filters, which stick to the metal with magnets and can thus be removed (and cleaned) without much trouble.
The fourth and final filter lies underneath the power supply. It slides out easily, even with the case screwed shut.
Our case-warmer build doesn’t normally change between reviews, but this time, we had to make special adjustments to account for the 250D’s form factor. Our full-sized ATX motherboard wouldn’t fit (duh), and neither would the microATX one we used inside the Obsidian 350D. Our Thermaltake Frio cooler was also too tall.
Instead, we used Asus’ P8Z77-I Deluxe motherboard along with Noctua’s NH-C14 cooler. The NH-C14 has a fairly low profile to begin with, and it can operate with its 120-mm fan sitting between the CPU socket and the fin array. Even in this arrangement, it was a smidgen over the 250D’s maximum 3.7″ cooler height. We were able to free up an extra 1.8″ or so of headroom by removing the 5.25″ drive bay—which, really, was no great loss. In the age of digital distribution, cloud backups, and Google Fiber, an optical drive can be much less valuable than a good CPU heatsink.
We also had to live without one of the 250D’s bundled fans, since our motherboard only has two fan headers in all (one for the CPU cooler and one for a single case fan). We decided to hook up the 140-mm front intake rather than the 120-mm side exhaust. The 140-mm intake should be able to pump more air, and its position at the front should translate into positive pressure inside the case. With only the 120-mm exhaust spinning, the pressure inside the case would be negative, and dust would get sucked in through the cracks and other unfiltered gaps.
Having only two fan headers isn’t uncommon among Mini-ITX motherboards, by the way. One has to wonder why Corsair doesn’t outfit the 250D with some kind of fan controller, or at least a three-pin-to-Molex adapter for powering the second chassis fan. I suppose the company may have designed this case with closed-loop liquid coolers in mind. With a cooler like, say, Corsair’s own H60i, the radiator would hug the side 120-mm fan, and there would be no need to power a third fan.
Given the relative awkwardness of using a large, conventional heatsink in a Mini-ITX system, perhaps that’s the route we should have gone. We had no spare liquid coolers on hand, however, and we wanted to conduct an apples-to-apples noise and heat comparison of the 250D and its larger siblings, which were previously tested with the Thermaltake Frio—a cooler not dissimilar from the Noctua NH-C14 in its basic design.
But enough about cooling. We have other nits to pick, starting with the 250D’s storage bay arrangement.
As we said, the drive bays are pretty straightforward to fill up. Unscrew the cover at the back, slide the trays out, snap them onto the hard drives and SSDs, and slide them back in. Easy. Hooking up the Serial ATA data and power cables is a little harder, though.
See, the drive trays are all stacked on top of one another, with the 2.5″ ones at the top, sandwiched between the motherboard and the 3.5″ trays. Because all four drive trays are lined up against the back of the case, the 2.5″ trays, which are shorter, don’t extend as far toward the front—and the front is where the connectors must go. Long story short, one pretty much has to push the 3.5″ trays out of the case to connect the SSDs. Even then, it’s hard to see what one is doing. We had to use an LED flashlight to get the job done.
Inserting the graphics card took a little finesse, too, especially since our XFX Radeon HD 7870 is fairly long, at 9.76″.
Again, because the motherboard lies flush against the back of the case, any expansion card’s I/O bracket must protrude outside. One must therefore hold open a sort of L-shaped guillotine during the installation process to make sure the bracket goes through it. Here’s how we did it: we lowered the card just above the PCIe slot, slid it horizontally toward the back of the case until the top of the I/O bracket stuck out through the guillotine, then pushed the card down into the slot, and fastened the bracket with two thumb screws.
The two thumb screws can be seen from this angle, as can the guillotine-like piece of metal that holds the I/O bracket in place. The guillotine is in its resting position here.
Happily, aside from these minor niggles, putting together our build inside the 250D was relatively uneventful. Everything worked as it should the first time around, and we like that Corsair reserves plenty of space between the board and the front of the chassis for cable routing. Our build was quite tidy, all things considered.
Still, throughout the building process, it was clear that Corsair had to make compromises to keep the 250D small. For the most part, those compromises made sense. However, they did mean the 250D wasn’t quite as easy to work in as a full-sized case—or even a slightly shrunken design like Corsair’s 350D. The clearances were tighter for just about everything, and the connectors had to be plugged in the right order to avoid blocking off other ports prematurely.
The payoff may be worth it, since the 250D lets one pack a full-fledged gaming rig inside a very small volume. Only one question remains: is the 250D’s cooling up to the task?
Our testing methods
Here’s a full list of the components we used for each case in our testing. Note that we used different coolers and motherboards to accommodate the different form factors. Our mobos were all Asus boards based on Intel’s Z77 platform, and our coolers were all large, heat-pipe-laden fin arrays with 120-mm fans. The results below may not amount to a strictly scientific apples-to-apples comparison, but they should be comparable overall.
|Case||Obsidian Series 250D||Obsidian Series 350D||Obsidian Series 750D|
|Processor||Intel Core i7-2600K|
|Motherboard||Asus P8Z77-I Deluxe (Mini-ITX)||Asus P877-M Pro (Micro-ATX)||Asus P8Z77-V LE Plus (ATX)|
|Memory||4GB Kingston HyperX DDR3 SDRAM at 1333MHz|
|Graphics card||XFX Radeon HD 7870 Black Edition|
|Sound card||N/A||Asus Xonar|
|Storage||Samsung 830 Series 128GB
Samsung Spinpoint F3 1TB
|Samsung 830 Series 128GB
Samsung Spinpoint F3 1TB
Asus Blu-ray burner
|Power supply||Corsair HX750W 750W|
|CPU cooler||Noctua NH-C14||Thermaltake Frio|
|OS||Windows 8 Pro|
We’d like to thanks Asus, Corsair, Kingston, Intel, Noctua, Samsung, and XFX for supplying all this excellent hardware.
We tested using the following applications:
The tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to discuss them with us.
Temperatures and noise levels
We used AIDA64 to keep track of temperatures for individual system components (the processor, GPU, motherboard, and storage drives) throughout a 40-minute period.
We left the system idling at the Windows 8 desktop for 10 minutes. Then we fired up the Heaven GPU benchmark and left it running by itself for 10 minutes. We then added a Prime95 CPU torture test to the mix and left it running, together with the Heaven benchmark, for 10 minutes. Finally, we stopped both tests and let the system cool down for the final 10-minute stretch.
Here are the results plotted over time. You can click the buttons below the graph to see temperatures for the different components:
Right away, we can see that our Core i7-2600K processor ran a fair bit hotter inside the 250D than in the other cases. Our Mini-ITX motherboard was warmer inside the 250D than its microATX and full-sized peers were in the other enclosures, too, and we saw marginally higher GPU and SSD temps inside the 250D—but only the CPU temperature is really a cause for concern.
The plots above depict broad trends. We can also show you some exact numbers. The bar chart below shows the minimum temperatures from the idle and cooldown parts of the run, and it also shows the highest temperatures recorded during the two load tests.
That 72°C figure is a little toasty for a 95W chip like the Core i7-2600K. More worrying still, the line graph above shows that our CPU temperature hadn’t fully stabilized by the end of our 10-minute full-load test. Since we’re thorough types here at TR, we kicked off a second full-load run and waited 20 minutes for the temperature to max out. It did—at around 78°C.
Yeah, that’s definitely a little toasty. The CPU didn’t throttle itself, however: AIDA64 reported a solid 3.51GHz throughout.
Of course, Prime95 is an extreme torture test, and running it alongside a graphics demo is, well, extreme-er. Real-world apps, even intensive ones, wouldn’t heat up the CPU quite so much. Additionally, the fan on our Noctua cooler was pointed toward the upper window, which lacks any venting, and we weren’t able to plug in the 250D’s side 120-mm fan, since our motherboard didn’t have enough headers for it. Had we used a closed-loop liquid cooler, with its radiator hugging the 120-mm fan on the 250D’s vented side panel, I’m fairly confident that our Core i7-2600K would have run cooler. We’ll have to do some further testing to confirm that theory.
For now, let’s have a quick look at noise levels before moving on to our conclusion. (As always, we used our TES-52 digital sound level meter to measure sound pressure.)
If you listen from the front or from the side, the 250D is a little louder than the other Obsidian Series offerings. Perhaps that’s because the XFX Radeon’s dual fans sit right up against an open vent. The noise isn’t bothersome, though. It’s very airy, a bit like a desk fan spinning away at the other end of the room.
So here it is. Corsair’s first stab at a Mini-ITX chassis—something cut from the same cloth as its other cases, but much more compact.
It’s a solid start, no doubt about it. The 250D combines small-form-factor dimensions with the amenities of larger enclosures in a way that’s inventive and usually quite effective. This isn’t the tiniest Mini-ITX enclosure around, but it may be one of the more straightforward ones to use.
Still, I’d be hesitant to call it a home run. Perhaps I’ve been spoiled by my experience with other Corsair cases, but the 250D seems to have more rough edges than the rest of the Obsidian Series. Hooking up the cabling for our SSD was awkward, for instance. Installing the graphics card took a few tries, and the cooling performance of our Noctua CPU heatsink was disappointing. We’ll have to see how the case fares with a closed-loop liquid cooler. For now, it’s clear that the limited vertical clearance and lack of venting in the top panel make it difficult to outfit the 250D with a typical aftermarket CPU heatsink.
None of this means the 250D isn’t worth checking out for your next Mini-ITX build, of course. I think it’s definitely worth a look. However, one must be careful in choosing components for it, and one must be aware of the extra difficulty involved in the assembly process. This case may be rife with tool-less features, and it may go to great lengths to favor ease of use, but deep down, this is still a Mini-ITX enclosure. As such, I’d recommend it only to seasoned PC hobbyists. An inexperienced user may find its cramped confines and cooling restrictions needlessly frustrating.