The 7 Smallest Micro-ATX Cases in 2022 – Voltcave

Micro-ATX motherboards aren’t quite as tiny as their Mini-ITX cousins, but they still offer helpful space savings vs. standard ATX boards. But since some mATX cases can be nearly as big as a mid-tower, you’ll have to choose carefully when building a compact mATX rig. And that’s exactly what our list of the smallest Micro-ATX cases will help you with.

We’ve defined a “small” Micro-ATX case as one that’s around 30 liters in volume or less (with one exception). This means that our picks should help you build a compact rig without too many headaches. We’ve also included a couple of bonafide small form factor (SFF) options for those who want to get really compact. Sound interesting? Let’s get on to the list.

Short on Time? The Best Small mATX Cases at a Glance

• Best Small mATX Case: SAMA IM01 is a compact 22-liter case that still has enough room and cooling capacity for high-end hardware.
• Runner-Up: SilverStone ALTA G1M is a tall case with a tiny footprint and excellent clearances.
• Best Small mATX Tower Case: SilverStone PS15 PRO offers great airflow in a small yet traditional tower shape.
• Small mATX Tower Case Runner-Up: InWin 301 trades optimal airflow for a super sleek tower design.
• Best HTPC mATX Case: InWin CJ712 is a tiny 8-liter case perfect for a home theater or office PC.
• Best Small Cube mATX Case: Thermaltake Core V21 isn’t small volume-wise, but its shape minimizes vertical size without compromising on component compatibility.
• Best Premium Small mATX Case: Sliger Cerberus is the best small Micro-ATX case hands down for those who can afford it.

Our Favorite Small mATX Cases

Best Small mATX Case

Measurements (H x W x L)12.12 x 7.40 x 15.64 inches

Motherboard SupportMicro-ATX, Mini-ITX

PSU SupportATX, SFX, SFX-L

Maximum GPU Length / Thickness13.19 inches (with SFX PSU) / 9.65 (with ATX PSU)

Maximum CPU Cooler Height6.1 inches (horizontal GPU) / 3.46 inches (vertical GPU)

Expansion Slots• Four horizontal
• Two vertical

Fan Mounts• 2x 120 mm (top)
• 2x 80 mm (rear)
• 2x 120 mm (bottom)
• 2x 120 mm (side with optional bracket)

Radiator Support• Up to 240 mm (front)
• 120 mm (rear)
• Up to 240 mm (side with optional bracket, Mini-ITX only)

Drive Mounts• 5x 2.5”/3.5” drives
• 7x 2.5” drives

I/O Ports• 2x USB 3.0
• Audio In/Out

The SAMA IM01 is the simple answer to a simple question: what if the Cooler Master NR200 (one of our favorite Mini-ITX cases) officially supported Micro-ATX motherboards?

The SAMA IM01’s angular design and aesthetics will be familiar to anyone that’s seen an NR200. But the IM01 differs in a few ways that make it an excellent choice for anyone seeking a compact mATX case.

Beyond the official mATX support, as mentioned earlier, the IM01 also supports full-size ATX PSUs at the cost of a few inches’ less GPU clearance in that configuration. This is a great feature if you’re going with Micro-ATX to avoid the “ITX tax” on smaller components. Of course, the IM01 supports SFX PSUs, too, in case you happen to have one of those on hand.

In addition to the ATX PSU support and multiple SFX PSU mounting options, you have the choice of a vertical GPU mount (at the cost of your maximum CPU cooler height). And you can also install an optional side panel bracket that supports two 120 mm fans or a 240 mm AIO (albeit only with an SFX PSU and Mini-ITX motherboard).

Options are always great to have, and the IM01 offers some decent ones. The only hiccup in recommending the IM01 is that concrete temperature data is hard to come by. That’s not unique to the IM01; that’s just par for the course when you buy relatively obscure Chinese cases.

However, judging by user reports and the ample ventilation on the top and side panels, you shouldn’t have any temperature issues in the IM01. It won’t compete with larger airflow cases, but there’s no reason why you can’t get usable temperatures in the IM01.

Overall, if you want a compact Micro-ATX case that still has enough room and cooling capacity for high-end hardware, check out the SAMA IM01. It has all the basics down and offers excellent value at its roughly $70 price. So much so that we wouldn’t blame you for getting the IM01 over the NR200, even for a Mini-ITX build!

Best Small Micro-ATX Case Runner-Up

Measurements (H x W x L)19.9 x 7.9 x 12.1 inches

Volume31.1 liters

PSU SupportSFX, SFX-L

Maximum GPU Length / Thickness13.9 inches

Maximum CPU Cooler Height6.25 inches

Expansion SlotsFour

Fan Mounts• 1x 180 mm (bottom)
• 2x 120 mm (rear)
• 2x 120 mm (side)

Radiator Support• Up to 360 mm (side)

Drive Mounts• 4x 2.5”/3.5” drives (without fans/radiator)

I/O Ports• 1x USB Type-C
• 12x USB 3.0
• 1Audio In/Out

SilverStone’s ALTA G1M is a Micro-ATX take on Mini-ITX cases like the Hyte Revolt 3. It’s not the smallest case here volume-wise, but it has a relatively small footprint that’s not that much bigger than the Revolt 3 and other similar cases.

You may be surprised to know that the ATMA G1M still only takes an SFX or SFX-L PSU, despite its 31.1-liter volume. However, there’s a good reason for that: going with a smaller power supply allows for excellent component and cooling compatibility.

Firstly, the 13.9 inches of GPU room is enough for almost any full-sized gaming GPU on the market right now. But what makes the G1M special is that there’s also enough space for a 360 mm AIO alongside the graphics card. That’s quite impressive considering the G1M’s shape and design.

You’ll likely want to make use of the radiator support, as the G1M only comes with a single 180 mm bottom intake fan. While you get mounting holes for 120 mm fans in the rear and side panels, they share space with the hybrid 2.5”/3.5” drive mounts. That’s probably the G1M’s only huge downside; having to choose between storage and cooling is usually a Mini-ITX problem.

TechPowerUp tested the G1M’s cooling prowess with an Intel Core i5-9600K and a Zotac RTX 3060 Ti Twin Edge OC running Doom Eternal. CPU temperatures were quite good at 66.1 degrees Celsius. The 3060 Ti’s 78.6 degrees Celsius was on the high side, though, even if technically within spec.

Reviews have also praised the G1M’s ease of use. There’s easy access to your PC’s components and a lot of cable management room at the top of the case for a clean build.

Overall, the SilverStone ALTA G1M is one of the most exciting Micro-ATX cases to come out in a long time. It’s not the smallest Micro-ATX case out there, but it’s a worthy contender if you’re OK with extra case height in exchange for a Mini-ITX-style footprint. The SilverStone ALTA G1M is also available in white.

Best Small mATX Tower Case

Measurements (H x W x L)15 x 7.56 x 13.8 inches

Volume25.7 liters

PSU SupportATX

Maximum GPU Length / Thickness12.3 inches

Maximum CPU Cooler Height6.06 inches

Expansion SlotsFour

Fan Mounts• 2x 120/140 mm (front)
• 1x 120 mm (rear)
• 2x 120 mm / 1x 140 mm (top)

Radiator Support• Up to 240 mm (front)
• 120 mm (rear)

Drive Mounts• 3x 2.5” drives
• 1x 2.5”/3.5” drive

I/O Ports• 2x USB 3.0
• Audio In/Out

Sometimes all you want is a standard tower case, just smaller. If that’s what you’re after, SilverStone’s PS15 PRO fits the bill. And unlike some of its competition, you get good airflow to boot.

The PS15 PRO is an updated version of the company’s old PS15, with all of the old case’s strong points. You have a mesh front panel for excellent airflow, an open interior layout, and thoughtful cable management features, including a dedicated cutout for your thick 12-volt ATX motherboard power cable.

The PS15 PRO also retains the older case’s excellent dust filtration, with removable filters for the top and bottom panels. The front panel’s dual-mesh layers handle filtration up front. It’s great that SilverStone didn’t feel the need to cut down on some of the PS15’s features to make room for the PS15 PRO’s extra fans.

Unlike the original PS15 (and some other small mATX towers), the PS15 PRO comes equipped with three 120 mm fans. You get two ARGB intake fans and a single non-RGB exhaust fan. This improved fan setup brings the PS15 up to the standard of pricier airflow-focused cases and means that you can run the PS15 PRO as it is without spending extra on fans.

We don’t have any test results for the PS15 PRO, but two 120 mm intakes with a mesh front should help keep most hardware reasonably cool. For context, Tom’s Hardware tested the old single-exhaust PS15 with a Core i9-7900X and recorded a 63-degree delta over ambient. That’s not too bad for a single exhaust and gives us confidence that temperatures will be excellent in the PRO.

Overall, the SilverStone PS15 PRO is the compact mATX case to go for if you want good airflow and a traditional tower design. If you already have a couple of 120 mm intakes handy, you can get the older PS15 for a slightly lower price.

Small mATX Tower Case Runner-Up

Measurements (H x W x L)14.3 x 7.4 x 14.9 inches

Volume25 liters

PSU SupportATX

Maximum GPU Length / Thickness12.2 inches

Maximum CPU Cooler Height6.3 inches

Expansion SlotsFour

Fan Mounts• 2x 120 mm (front)
• 1x 120 mm (rear)
• 2x 120 mm (bottom)

Radiator Support• Up to 240 mm (front)
• 120 mm (rear)

Drive Mounts• 2x 2.5” drives
• 1x 2.5”/3.5” drive

I/O Ports• 2x USB 3.0
• Audio In/Out

The InWin 301 sticks out from the pack with its sharp, minimal design and relatively premium materials. The screw-less tempered glass panel perfectly matches the solid front panel, giving the 301 a classy look that belies its affordable price.. It’s one of the best-looking cases on our list.

Thankfully, the InWin 301 isn’t all style. The 301 has a relatively roomy interior for its size for easy assembly. InWin also included thoughtful features such as a built-in GPU support bracket and removable push tabs for cable management.

On the negative side, the 301’s drive mounting options are limited, with space for a maximum of three drives simultaneously. The accessibility of M.2 SSDs makes that a much smaller problem now, but it’s still something to be aware of if you’re trying to migrate a drive-heavy rig into the 301.

The InWin 301’s biggest issue, though, is its default fan setup. This combination of price and materials means that InWin had to cut corners somewhere, and it did so by shipping the 301 without any fans. Predictably, this makes for mediocre stock temperatures.

A 61-degrees Celsius delta on a 4.0 GHz overclocked Intel Core i7-4670K isn’t great. Neither is the 55-degree GPU delta they recorded on a GTX 980. Fortunately, even a couple of fans should help bring temperatures down significantly, although the 301 likely will always run a bit hot due to its closed-off front panel.

The InWin 301’s combination of great looks and affordable price makes it still worth considering in our book, despite its flaws. If you’re willing to trade some features and cooling performance for a stylish and smaller-than-average compact mATX tower, the InWin 301 is it. The InWin 301 is also available in white.

Best HTPC mATX Case

Measurements (H x W x L)12 x 3.7 x 10.9 inches

Volume7.9 liters

PSU SupportFlex ATX (built-in)

Maximum GPU Length / Thickness9.9 inches

Maximum CPU Cooler Height1.8 inches

Expansion SlotsFour (low-profile)

Fan Mounts• 80 mm (front)

Radiator SupportNone

Drive Mounts• 1x 2.5” drive
• 1x 2.5”/3.5” drive

I/O Ports• 2x USB 2.0
• 2x USB 3.0
• Audio In/Out

Let’s get it out of the way: the InWin CJ712 isn’t the best Micro-ATX case if you want to build a high-performance gaming PC. But if you’re building a low-power mATX computer, it might be the perfect case for you.

The CJ712’s biggest selling point is its diminutive size. At just under 8 liters in volume, it’s smaller than even most mainstream Mini-ITX cases, let alone other Micro-ATX cases. Of course, this does come at the cost of CPU cooler compatibility and overall cooling performance, but that won’t be an issue if you select suitable components.

You still have enough space for a decently-sized GPU, although we don’t recommend just chucking any GPU in the CJ712. For one, the single 80 mm intake fan doesn’t offer enough airflow for gaming-grade GPUs. On top of that, the built-in PSU is only a 265-watt unit, too low even for mid-range cards.

You can swap the PSU for a beefier one, which will allow you to install something like a Zotac GTX 1650 LP in the CJ712. However, a 350-watt Flex ATX PSU like the SilverStone FX350-G costs nearly as much as the CJ712 itself. At that point, you might as well get a different case that’s more suited for a compact gaming rig.

We recommend using the InWin CJ712 the way it was arguably intended: as a low-power HTPC or office PC, where cooling and 3D performance aren’t of huge importance. It’s perhaps a bit of a niche use case, sure, but it’s great if you want a sub-10 liter case without the increased cost of Mini-ITX.

And, as a bonus, it fits perfectly in an IKEA Besta TV cabinet. If that isn’t a sign that it’s the perfect slim Micro-ATX case for an HTPC build, we don’t know what is.

Best Small Cube mATX Case

Measurements (H x W x L)13.2 x 12.6 x 16.7 inches

Volume45.5 liters

PSU SupportATX

Maximum GPU Length13.8 inches

Maximum CPU Cooler Height7.3 inches

Expansion SlotsFour

Fan Mounts• 2x 120/140 mm / 1x 200 mm (front)
• 4x 120 mm / 2x 140 mm (top)
• 1x 120/140 mm (rear)
• 2x 120 mm (bottom)
• 2x 120/140 mm (side)

Radiator Support• Up to 240 mm (front)
• Up to 280 mm (top)
• 120 mm (rear)
• Up to 280 mm (bottom)

Drive Mounts• 3x 3.5”/2.5” drives
• 3x 2.5” drives

I/O Ports• 2x USB 3.0
• Audio In/Out

The Thermaltake Core V21 is 45.5 liters, so it’s not necessarily a “small” case. However, its cube shape gives you more placement flexibility, which might help it fit where conventional tower cases won’t.

Thermaltake’s Core V21 is one of the older cases on our list, which shows in its frankly outdated aesthetics. But behind that dull exterior is a great case whose flexibility and options keep it relevant despite its age.

Options are the name of the game here, and it starts with the motherboard. The Core V21 supports horizontal and vertical motherboard installs, both of which split the internals between the heat-generating components (CPU, GPU) and your drives and power supply.

The Core V21’s cube form factor also gives you many options for your cooling setup. You get a ton of fan mounting options and enough space to run a couple of radiators simultaneously. The Core V21 only ships with a 200 mm intake from the factory, so you’ll likely want to use additional case fans to help the airflow situation.

Hardware for Games found that adding even a single 120 mm exhaust fan drops temperatures significantly, bringing a 68 degrees Celsius delta on the CPU down to a more manageable 60 degrees. GPU temperatures saw a similar drop, from 64 degrees stock to 60 degrees as well.

If temperatures are your priority, you can also experiment with removing the dust filters to improve the temperatures significantly. Of course, that’ll increase the amount of dust that gets into your rig, but that’s nothing some regular cleaning can’t overcome.

Overall, the Thermaltake Core V21 is solid, if slightly old-fashioned. Its cube shape won’t be for everyone, but it’s perfect for minimizing your rig’s vertical size without compromising on component compatibility or radiator support.

Best Premium Small mATX Case

Measurements (H x W x L)12.6 x 6.8 x 14.1 inches

Volume19.6 liters

PSU SupportATX, SFX, SFX-L

Maximum GPU Length / Thickness13 inches

Maximum CPU Cooler HeightATX PSU:
• 1.9 inches

SFX PSU:
• 2.9 inches (PSU on rear plate)
• 5.8 inches (PSU with internal mount kit)

Expansion SlotsFive

Fan MountsBase chassis:
• 2x 120 mm (front)
• 2x 120/140 mm (bottom)
• 1x 120/140 mm (side, vented panel only)

Optional:
• 1x 120 mm (handle bracket)
• 1x 120 mm (ATX PSU with top mount bracket) / 2x 120 mm (SFX PSU with top mount bracket)
• 1x 92/80 mm (SFX internal mount kit)

Radiator Support• Up to 240/280 mm (bottom)
• 120/140 mm (front)

Drive MountsBase chassis:
• 2x 2.5” drives

Optional:
• 2x 2.5” drives
• 3x 3.5” drives

I/O PortsChoose between:
• 2x USB 3.0
• 1x USB Type-C + 1x USB 3.0
• 2x USB Type-C

There’s no way around it: Sliger’s Cerberus is an expensive case. However, its combination of SFF dimensions, component compatibility (including room for multi-GPU setups!), and exhaustive internal mounting options makes it a unique offering as far as compact mATX cases go.

Looking at our specs table above should tell you that Sliger’s covered almost all of the bases when designing the Cerberus. Not only are there three different PSU mounting options, but you can also kit your Cerberus out with extras like a handle or a top-mount fan bracket, as well as add more storage brackets for extra drives.

The Cerberus also boasts an “infinite vent pattern,” which allows you to install 60 to 140 mm case fans “almost anywhere.” That’s handy in a case this small and is another bit of flexibility that you generally don’t get in mainstream cases.

Unsurprisingly for such an enthusiast-minded case, the Cerberus doesn’t ship with any fans. Given all the options available, it makes sense that Sliger would trust the end-user to install their own fans. That said, the company does recommend users stick to a conventional two-intake, one-exhaust setup for optimal temperatures.

Of course, the downside of all of these options is that the Cerberus works best if you know exactly what you want to do with your rig. It’s awfully easy to get bogged down by all the options if you’re still uncertain about your components or setup.

Sliger also offers a handful of aesthetic choices for the Cerberus, keeping with the general theme of user choice. You can choose from a few panel colors (including custom colors if you’re feeling fancy), whether you want a black or matching top panel, and the finish on the feet and handle.

The Sliger Cerberus isn’t for everyone, but it’s perfect if you want what it offers: the most options and gaming rig potential in the smallest Micro-ATX case possible. If that’s your goal, the nearly $300 price is arguably a small one to pay.

Closing Thoughts

The quest for the smallest Micro-ATX case isn’t necessarily a straightforward one. Not every mATX case is genuinely compact, and you can’t just rely on a case’s motherboard support to guarantee its size. Hopefully, our list has helped you narrow down your search to a couple of options.

The SAMA IM01 or SilverStone PS15 PRO are the cases we’d recommend to anyone who wants something straightforward to build in. The PS15 PRO, in particular, should be familiar if you’ve built in an ATX tower before. But every case on our list has something unique to offer and is well worth investigating if you’re just browsing.

Unsure whether you want to go with Micro-ATX or Mini-ITX? Check out our guide to motherboard sizes for some tips and advice.