A small form factor gaming (SFF) PC or mini gaming PC is just what it sounds like: a computer designed to take up less space. As creative builders and manufacturers continue to push the boundaries of what’s possible with this form factor, smaller PCs continue to increase in popularity and accessibility.
The size of these mini gaming PCs offers distinct advantages, like better portability for your next LAN party and more flexible placement in spaces that might not work with a traditional desktop tower. For a long time, though, experimenting with SFF meant sacrificing gaming performance or functionality to get that smaller footprint. That’s changed over the last few years. Now, a full-fledged PC gaming experience is accessible in a smaller package.
What Qualifies as “Small Form Factor”
What exactly qualifies a PC as having a small form factor?
There isn’t a universally agreed-upon definition, but there are some loose guidelines tied to case measurements. When discussing the internal layout and size of PC cases, volume is often an important consideration, and is usually measured in liters. A standard-size ATX desktop tower is usually around 40-45 liters. By comparison, a common measurement for SFF is around half of that — 25 liters or less.
However you define SFF, there’s a lot of information out there about building in this unique form factor. Here’s what you should be thinking about when planning your build.
How to Choose a Pre-Built SFF PC
Maybe you’re interested in an SFF gaming PC but don’t want to build your own. Fortunately, there are plenty of options when it comes to pre-built SFF PCs, with a variety of shapes, sizes, and specialties from which to choose.
- Don’t underestimate pre-built SFFs. If you’re looking for a powerful desktop gaming experience in a smaller body, there’s a wide selection of pre-built SFF PCs built with top-of-the-line gaming hardware, like the latest gen Intel® Core™ processors and NVIDIA GeForce RTX GPUs.
- Consider shopping by brand. Some of the biggest brands in PC gaming offer pre-built SFF gaming PCs, so if you’re interested in picking up a small gaming PC that’s ready to go, simply search your favorite brand’s offerings and take your pick.
How to Build Your Own SFF PC
If you’re looking to build your own SFF gaming PC, there are more options to work with today than ever before. Many systems under 25 liters can now utilize the same components you might find in a standard mid-tower that's more than twice the volume.
Still, building an SFF PC has a different set of challenges than working in a standard mid-tower ATX case. The fundamentals of building a gaming PC are more or less the same between a full-size gaming computer and an SFF PC, but there will be less space to work with, which can make steps like component selection, installation, cooling, and cable management more complex.
To try and simplify the process, we’re going to tackle each component individually and touch on some of the factors you’ll want to consider when putting together your own mini gaming PC.
SFF PC Components & Hardware
Your case is probably the best place to start, as it will dictate the amount of space you have to work with.
- Pay close attention to the CPU cooler and GPU. If you already have components selected or on hand, make certain the case you choose will properly house them. If you haven’t yet purchased your hardware, make sure you select a case that will accommodate the length, width, and height of every piece of hardware. The CPU cooler and the GPU deserve the most attention.
- Don’t neglect the case’s aesthetics. Beyond just performance and liter count, what do you want your build to look like? There are vertical builds that stand like smaller, traditional towers, or cases that allow vertical or horizontal placement. There are shoebox-shaped cases, as well as unconventional desk-like designs, such as the Cryrog Taku*. Are you interested in a window so you can see your components in action? How about a handle to make your small PC conveniently portable?
- Take advantage of online resources. When it comes to specific case clearances and compatibility questions, you’ll likely find forums, message boards, and online SFF communities as excellent places to look for answers. Chances are, if you have a question, someone out there has asked it, too.
Once you’ve selected your case, you’ll have a better idea of how to choose a motherboard as your range of options will be heavily impacted by the size of the case.
- Anticipate using a smaller motherboard. Though there are SFF cases that support full-size motherboards, it’s likely that you’ll end up with a smaller motherboard — most likely Mini-ITX, or a slightly larger microATX if you’re looking for more flexibility.
- Choose the right motherboard configuration for you. Motherboards come in a variety of configurations. Many offer a full suite of features despite the smaller surface area and can still provide everything you need for a high-end gaming build.
- Don’t be afraid to be creative. Many limitations you encounter — for example, having access to only one PCIe slot — can be overcome with creative hardware configurations, like looking for M.2 alternatives to full-size PCIe slot devices, installing higher capacity RAM modules, or utilizing PCIe riser cards for your GPU to allow for more diverse positioning.
Again, your exact configuration will depend heavily on the case you’ve chosen, but seeing the motherboards that other people used in conjunction with your case could be a useful place to start.
GPUs come in a variety of sizes to support SFF builds. There are plenty of GPU form factors to choose from, including single-slot, low-profile, or half-length configurations, but many cases have recently begun supporting full-size components, too. This widens your options when it comes to SFF cases as you no longer have to plan around an unconventionally sized GPU.
- Be thorough in considering measurements. When you research the measurements provided by the GPU manufacturer, or the GPU size allotment of your case, keep in mind that they might not take into account the PCIe power supply connectors or the bracket holding the card. These two factors can add substantial height (or width, depending on the orientation of your GPU) that need to be accounted for when planning your layout. This can be challenging to solve for, as, again, it will depend on your particular configuration.
- Look into solutions for space management. Factoring in a little bit of extra space around your GPU when considering the placement of your other components could be useful, as is consulting others who have used your case. There are also options like PCIe power cable relocation solutions or riser cables that might be worth exploring.
- Your SFF case may not support all GPUs. While many SFF cases support full-size GPUs, that doesn’t mean universal support. Large, multislot GPUs might not be compatible with your case, so you’ll still need to carefully consider the height and width of your GPU and plan accordingly.
- Cooling solutions can help save space. If you want a bit more flexibility when it comes to the form factor of your GPU, there are also aftermarket air and liquid cooling solutions that might provide some flexibility when it comes to size as well as potentially quieter and cooler operation.
The CPU is one of the few pieces of hardware that isn’t heavily impacted by choosing a mini gaming PC. As long as it's compatible with the motherboard you've selected, you should be good to go! If you require more guidance, check out our guide on how to choose a gaming CPU.
The CPU may not be impacted by going SFF, but the CPU cooler very well could be. Whether you’re planning on using air cooling or liquid cooling, there are plenty of low-profile cooler options to choose from.
Low-profile fan coolers are often the simplest choice in SFF builds. While it is possible to implement a liquid cooling solution, again, it’s probably going to come with more challenges than a standard-sized build.
All-In-One (AIO) liquid coolers require a radiator to function properly, and depending on your case, this could cause clearance issues.
Custom cooling loops add even more complexity, as working with pumps and tubing in such a small space can be a serious logistical challenge.
Another point to consider: your choice of CPU cooler could also impact your RAM options. A low-profile cooler might require low-profile RAM, depending on your configuration, so be sure to consider the clearances between your CPU cooler, motherboard, RAM, and chassis.
When choosing RAM for your SFF PC, you’ll need to take your motherboard and case size into account. Standard-sized modules should work in most motherboards, including Mini-ITX, although there are a few limitations to consider.
- Many Mini-ITX boards have only two RAM slots. You can still equip your PC with 16 or 32GB of RAM via higher single-stick capacity DIMMs, but decisions need to be made in the planning stages based on how much memory you'll need over the life of your system.
- Single channel memory may limit your system’s performance. Unlike full-size motherboards, where having empty RAM slots is sometimes appropriate if you plan to upgrade later, using only one stick of RAM, regardless of capacity, can limit your system by not allowing access to the bandwidth afforded by dual-channel memory. Make sure to check the maximum capacity of single-channel memory on your platform and whether or not your motherboard supports dual-channel.
- Look into SO-DIMM RAM. If you’re looking at a very small form factor, you might need SO-DIMM (Small-Outline Dual-Inline Memory Module) RAM, commonly found in laptops.
With most motherboards, you typically have a fair amount of flexibility in choosing between an SSD or HDD for storage, though you might be limited by the physical parameters of your case. You might have SATA ports on your motherboard, but whether you have space for a 2.5 or 3.5-inch SATA storage drive is going to depend on your particular setup.
The M.2 storage form factor solves a lot of these potential issues. These storage devices plug directly into your motherboard, eliminating cables, and the smaller size fits nicely with the goals of SFF. Many Mini-ITX motherboards even support multiple M.2 drives, though keep in mind the placement of those drives. Small spaces, like the one between the case and the underside of the motherboard, can result in the M.2 overheating if there is insufficient cooling, which can cause performance issues.
You’ll also need to select a power supply unit (PSU).
- Determine whether or not the case supports a full-size PSU. Many support full-size power supplies, but if not, you might need to go with the SFX form factor. These PSUs are designed to be more compact, and to provide more flexibility in placement.
- Consider a modular power supply. A modular power supply allows you to choose the cables you put in your build by allowing you to pick and choose only those you will use. This flexibility allows for a cleaner build, which can make a substantial difference when you’re working in a small space, and can help with airflow as well.
- Try custom-length cables. If you’re finding that cable management is an issue in your case, you can find PSU cables designed to custom lengths, allowing you even more flexibility.
Check out this power supply guide for more information on selecting the right PSU.
Selecting hardware that fits in your case is the first step to putting together an SFF gaming PC. Making sure everything is properly cooled is the second. Thermals and cooling can be one of the more challenging parts of building small computers; all of those powerful components operating so close together creates heat, and removing that heat is important.
- The smaller you go with your build, the more difficult it becomes to manage thermals. This is especially true if you’re overclocking(2) your hardware or pushing higher temperatures over sustained periods of time. Testing your build with demanding workloads and closely monitoring component temperature and performance is a great way to ensure that you're within the operating limits of your hardware and is also a good way to identify problems as they arise.
- Make sure your cables are properly managed. With SFF gaming PCs, it’s critical to ensure that the cables are not inhibiting the ability of any active cooling (like preventing a fan from spinning), or blocking any airflow pathways.
- Carefully consider your fan placement. Properly using all the fan mounting locations in your case can go a long way toward ensuring proper airflow. You’ll want to balance the fan configuration between intake and exhaust, and focus on creating pathways that effectively relocate the hot air generated by your hardware to the outside of your system.
- Seek assistance online. If you’re looking for assistance in determining your ideal fan and cable configuration, your case’s manual or website is probably a good place to start. Another excellent resource is online SFF communities. Reviewing completed systems that used your same case can be a great way to draw inspiration, and answer questions or shed light on issues you might encounter during your build.
Building an SFF gaming PC doesn’t mean you have to compromise on power or features.
Though the smaller form factor presents some unique logistical and thermal challenges, the variety of SFF hardware available means you can customize the build you want in the smaller size you’re looking for.
If you’re a PC enthusiast with a few builds under your belt, maybe the challenge of a mini gaming PC build is the next step in your PC building career!