The Best Compact PC Cases to Put on a Desk

The Lian Li O11 Air Mini is one of the most compact cases that either support an ATX motherboard or Micro-ATX and a top-mounted radiator. The rear panel is modular, so you can install it according to your current hardware. The case uses a dual-chamber design to save height, with the PSU and up to six SATA drives, of which up to four 3.5" HDDs, in the other chamber.

After an initial recall and replacement of the mesh panels, airflow is good with two 140mm fans in the front and a 120mm one at the rear. With an ATX motherboard, radiators of 240mm can be installed at the bottom or on the side (if you remove one of the dual-HDD plates), but 280mm ones can only be installed in the front. With a Micro-ATX motherboard you'll also be able to install the latter on top (in mATX mode) or at the bottom (in ATX mode).

Other than that, the side window is made of tempered glass, and the bottom dust filter is easily removable from the side. The top I/O includes three USB 3.0 ports, including one Type-C. The case is available in black or white, for $110 and $121 on Newegg, respectively.

A case that almost made it into our list of best old-school cases, the Cooler Master HAF XB Evo includes two 5.25" bays and four SATA drive bays (2 of which hot-swappable) in 3 removable cages. Unlike the Lian Li O11, this ATX case saves height by mounting the motherboard horizontally, on a removable tray, above the drives and PSU.

The CPU and graphics card are kept cool with two 120mm fans in the front. Those can be replaced with a 240mm radiator or 140mm fans, but 280mm radiators aren't officially supported, except the Nepton 280L. You can add a 200mm fan on top, a 120mm one at the rear, and two 80mm ones behind the SATA drive cages.

The front I/O is very convenient to use while sitting in front of the case. It only includes Type-A USB 3.0 connectors, but thanks to the 5.25" bays you can add any connector you want. Despite its size, the case is easy to carry thanks to large handles on the sides.

If you have a Micro-ATX motherboard, then the Thermaltake Core V21 will offer you the best value at $70. The case includes 5 expansion slot covers, even though mATX cases only support 4 expansion slots, in case you install a multi-slot card in the bottom slot.

This case doesn't just look like a cube, but also works like one. Its main body can be installed in any orientation on the bottom panel. If you have a graphics card, the default orientation with the motherboard mounted horizontally will provide the best distribution of weight (and a removable filter for the PSU). If not, you may want to rotate the main body 90 degrees so that the PSU and the CPU cooler are both near the bottom. The Thermaltake logo is printed on a magnet that you can rotate accordingly.

The top and side panels are interchangeable, so you can choose where to put the acrylic side window (beware not to choke your graphics card with it). The other two panels offer large vents with magnetic filters.

With a 200mm fan in the front, the V21 has no issues with cooling. You can also install a 120mm or 140mm fan at the rear, and a 280mm radiator in 3 different locations. In one of those locations, you can install it next to a 240mm one!

The PSU chamber supports up to six SATA drives, of which up to three 3.5" HDDs. The case only offers Type-A USB 3.0 and no 5.25" bays (even though the main body has the space for one), but for the price it's hard to complain.

If you want the absolute most compact case that can fit a Micro-ATX motherboard, look no further. This case doesn't even waste space on a PSU chamber, but puts the PSU in the front, drawing air through the sides of the front panel and releasing it through the perforated top panel (the external power cord still connects to the rear of the case). If you have a tower-style CPU cooler, you may want to rotate it 90 degrees in either direction if possible, as it won't get direct airflow from the front.

The case only comes with one 80mm rear fan, but you can add another one, as well as three 120mm ones: 1 on top and 2 at the bottom. The bottom spots can also be used for SATA drives, and another one can be installed behind the PSU. Unless you use both of the bottom spots for HDDs, you can install another SSD under the PSU.

The front panel has two USB 3.0 Type-A connectors on top. For about $70, it's a good value. The main feature completely missing is dedicated cable management space, so you'll want to use a modular PSU with this case.

Even if you need 10 disk drives in a single package, you don't have to buy a full ATX case. The Fractal Design Node 804 can house 8 of those in two cages in the PSU chamber, and 2 more on the floor of the motherboard chamber. The front panel has space for 2 SATA SSDs and a slim optical drive.

Each chamber comes with its own 120mm rear fan. In the PSU chamber, you can replace it with a 140mm one. That chamber can also house a 280mm radiator on top (instead of the drive cages…), while the main chamber supports 240mm (or two 140mm fans) as long as your RAM isn't too tall. Each chamber also supports two 120mm front fans (the motherboard chamber comes with one), but because of the shape of the front panel, one in each chamber would be enough. That's also why we don't recommend installing 240mm radiators in the front, even though each chamber supports one.

Like the ThermalTake Core V21, the case has 5 expansion slot covers, but if you install any card in it, you should move the front fan to the bottom of the panel to help cooling it.

Each chamber also has its own removable dust filters at the bottom and behind the front panel. The rear of the case includes a physical 3-speed fan controller, and on the side of the front panel are two USB 3.0 Type-A connectors.