Lian-Li PC-Q11 is a pretty large case. I always call it a no-compromise Mini-ITX case because it pretty much has everything an ATX mid-tower would have: 5.25” ODD bay, 3.5” and 2.5” drive rack and ATX PSU. You lose some CPU heat sink clearance (it only has 80 mm), but it does not stop you from using the fastest consumer i7. Video card length is capped at 240 mm, but that has become less of an issue thanks to the incredibly power efficient Maxwell GPU.

The list does not stop here. The PC-Q11 can even house a microATX motherboard. I realized this when staring at my Q11 and trying to figure out what to do with the $80 G3258 + H81 combo from Newegg. A quick search on the Internet shows that people have been taking advantage of this “feature” back in 2011. I guess I am late to the party.

Not every microATX would do, of course. The length of the motherboard must not exceed 244 mm or 9.6”, the maximum allowable length of microATX. If you do bring a motherboard that is 244 mm long, it would fit but it would also interfere with 3.5”/2.5” drive rack. Guaranteed compatibility requires the length of the motherboard be no greater than 23.5 cm, corresponding to the lower edge of mounting hole “R” according to ATX Specification Ver. 2.2.

ATX Spec
The specification has a motherboard in landscape orientation, which is a little strange because normally we see a motherboard in portrait orientation when installed in a typical ATX case. Here in this article when I use terms like “left/right”, “upper/lower”, “vertical/horizontal”, etc., I am looking at the motherboard in portrait orientation.

Width-wise the boundary is not as clear. To guarantee compatibility you should stay within Mini-ITX (17 cm * 17 cm) as much as possible because two things can cause interference, the front in-take fan and the front-panel connectors (two USB 3.0 and two audio jacks). The right hand side of a motherboard is usually a cluster of internal connectors, such as 24-pin power, SATA, 20-pin USB 3.0, etc. Even if size-wise a motherboard fits, you might not be able to access all the on-board connectors.

Of course you do not have to be conservative. Here is an example of PC-Q11 pushed to the limit. The ASUS P8P67-M measures 24.4 * 22.3 cm, but again from the photos it is obvious that you have to remove basically everything from the front panel (power/reset switch unit, fan mount, USB and audio jacks). Also notice that the four metal stands for installing these parts are not removable. Therefore I doubt you could easily put the motherboard in if it is full-size microATX (24.4 cm * 24.4 cm). The other two parameters for reference are the maximum video card length (240 mm) and the depth of PC-Q11 (260 mm).

What kind of microATX motherboards can I get at this size?

How far you want to go beyond the width of a Mini-ITX is really personal preference. I find myself more of a minimalist when it comes to modification, so again I would stay within 17 cm width as much as possible. The motherboards you can get at this size actually have a pretty clear pattern. Most of them use low-end chipsets such as H61 and H81. There are a few B series as well. Width is typically the same as Mini-ITX (17 cm) or stays very close (~18 cm). Length is technically arbitrary, but most manufacturers go with ATX mounting holes, so you can use them as reference points.

  1. Half-way between mounting holes “C” and “B”, typical length 19 cm. e.g. ECS H81H3-M4
  2. A little over mounting holes “B” and “S”, typical length 22.6 cm. e.g. MSI H81M-P33
  3. Mounting hole “R”, typical length 23.5 cm. e.g. BIOSTAR G31-M7 TE
  4. Full-length (24.4 cm) microATX. e.g. Gigabyte GA-H81M-DS2V

This is not a exhaustive list, but includes the four main types.

Type #1 is what comes up first when you sort by “Lowest Price” on Newegg. They are cheap but there is something you need to watch out for. On these motherboards the PCIe x16 slot is placed in the second PCI slot position, which does not line up with the PCI expansion slot on most Mini-ITX cases (because they will only have one, the very first one). If you plan to use a discrete video card, you should stay away from type #1.

GA-H81M-DS2V is actually a special case in #4 because the board has nothing beyond mounting hole “R”, basically a type #3. Otherwise it would be incompatible with PC-Q11 because of the 3.5”/2.5” drive rack. Typically the very bottom of a motherboard is dedicated to internal jumpers for front panel connectors (USB, power/reset/LEDs, audio, etc.). You should stay away from full-length microATX unless you are willing to sacrifice 3.5″/2.5” capability.

Generally motherboards become more expensive as they grow in size. Once you go beyond $75, a microATX is unlikely to fit comfortably in the PC-Q11 without causing compatibility issues, due to either width or length.

Which brings me to my final point. Even though PC-Q11 has room to accommodate larger than Mini-ITX, the best motherboards it can take are still Mini-ITX, simply because no one makes a high-end microATX that is only slightly larger than Mini-ITX. It is such a tiny niche in the market that no manufacturer cares enough to fill something in.

That is kinda sad.

But isn’t it a niche worth exploring though? Nowadays gaming-oriented Mini-ITX cases usually support two PCI expansion slots, so the case must be longer than (approximately) length of Mini-ITX +  thickness dual slot video card, which I believe would be around 19 cm. Why not make a high-end “Mini-ITX+” that is 19 cm by 17 cm? There you get 2 cm of extra room to operate while still assuring compatibility with most Mini-ITX cases. Maybe put the audio and Ethernet controller below the PCIe and save some room for a beefier VRM? This way you can possibly get a better audio circuit, too.

For some Mini-ITX users, what they really need is thin Mini-ITX which is a true small form factor. Mini-ITX, on the other hand, should evolve and become Mini-ITX+, and target a higher-end market.