Small Form Factor Builds (SFF) have a small but devoted following. You’ll find small boards and threads all over the internet. I am not an expert, but I spent a lot of time researching before I did my small build.

Shortcuts:

• Building a Small Form Factor Personal Computer (SFF PC)
• Motherboard
• SFF Cases
• Graphics Cards
• Power Supply
• Processor
• Storage
• Operating System
• Example Builds

Why Small Form Factor?

This is a good question to ask yourself. Why do you want to build a small computer and what about it fascinates you? This is really the most important question you can ask since it will determine what you’ll focus on for your build. I’ve broken it down into 3 types of builds:

1. PCs Are Too Big: Small Build

You’ve been looking around and all the cases are huge, or your current case is huge. You want to build something smaller, but you don’t need to obsess about size. This type of build is about having a computer that doesn’t fill your desk. You can use lower priced components, get better cooling, and not have to play Tetris with your computer.

2. Extreme Gaming: Power Build

You want the best frame rates, RGB, in a cool case that isn’t huge, and you can show it off to noobs, when you carry it in by its built-in handle. This build can still be small, but you must take into account cooling and display. This is the one that’ll break your budget and it’s beauty will make you cry.

3. How Small is Small? SFF Build

You want to see how small you can go with standard components. I say standard components because there are a lot of proprietary SFF PCs built by manufacturers (the Intel NUC comes to mind). You want something you can tinker with, upgrade, and put together yourself…and you want it as small as you can get it.

Building a SFF PC

Ok, now that we’ve answered why we want Small Form Factor and what kind of build we want, we have to go build it. Let’s start with Components:

Motherboard

The ATX (Advanced Technology eXtended) is the standard that motherboards are sized by (and consequently: cases). Here are the standard sizes of boards:

The motherboard is often the largest thing in the case so it’s size is the biggest limiting factor. ITX boards are what most SFF builds use (Note: ITX boards fit in larger ATX cases too). Micro ATX is a good low price option because they are cheaper and have more PCIe slots and Memory Slots. Here’s a quick rundown of motherboard specifications:

• Socket – It’s either gonna be AMD or Intel. Pick your team now. You’ll be stuck with them for a while. They go back and forth on who’s got the best stuff.
• PCIe – This is where you connect your Video Card. You can connect other things here, but if you’re going to have your screen, keyboard & mouse connected directly to it, you probably don’t need a second slot. The generation of PCIe is important too. Gen 3.0 is good enough for most stuff you want to do (including gaming), but high end gaming requires PCIe Gen 4.
• Memory Slots – This is for your RAM. Less slots means you need bigger ram sticks. So if you want 128gb of ram (who doesn’t?) a ITX board is more expensive (64×2) than a Micro (32×4 or 16×6).
• Chipset – If the CPU is the CEO then the Chipset is the Logistics Manager moving around information from all the stuff on the board. For a Power Build you need top tier chipsets, but for everyone else a second tier is fine. Let’s break it down by teams blue & red:
  • Intel (Team Blue): The Z series chipsets are top tier (Z490 & Z590). Second tier is the H series (H370). The B Series will do if you’re a mid-level gamer (B660).
  • AMD (Team Red): X series are your top tier here (X570 & X470). Second tier is the B series (B550). Even A series will do in a pinch (A520).
• Onboard Video – You can get by without a Video Card (requires CPU w/integrated graphics).
• Wireless – Check to make sure the motherboard has WiFi & Bluetooth. Not all do.

SFF PC Cases

This is the most important thing to think about when designing your SFF PC (unless you want to go caseless, yes that’s a thing). The biggest limitation to your build is the components. You gotta fit all the stuff in there, so figure out what you’re working with and then see what fits. Here are the big offenders:

• Motherboards – Yeah, they tend to be the biggest thing.
• Air Cooling – If you’re making a beefy machine you need space for the air to flow.
• Water Cooling – Depending on what you’re cooling you’ll need space for this stuff:
  • CPU: an all-in-one (AIO) is just that No messing around with pipes and filling
  • GPU: If you go this route, you’re building a full cooling system with lots of futzing around. This’ll take up even more space (14+ liter cases).
• Power Supply – This can limit a few things.

Once you know what you’ve got, go find what case it’ll fit in. Most SFF builds go air cooling. You can search for an ITX case and then start looking for dimensions. Some standards say less than 9 liters, but you’ll be hard pressed to get under 4 liters. Here’s a short list of tiny cases I’ve found:

• Densium 4 V2 (4.5L) – Extremely small, ITX, 222mm GPU, Flex PSU, $159
• Kab1ou ZZAW A1 (5.7L) – Small, ITX, 205mm GPU, Flex PSU, $105
• SGPC K49 (7L) – SFX PSU, 300mm GPU, Acrylic side panel, $100
• Sliger cl520 (8.1L) – SFX PSU, 324mm GPU, Flat DVR design, $200
• Louqe Ghost S1 (8.47L+) – Expandible, Expensive (all varies on expansions)
• Lian Li Q58 (14.53) – Can fit water cooling, Glass Window, 320mm GPU, $141
• Cooler Master Elite 110 (15.3L) – Good Airflow, almost cubic, AIO, 210mm GPU

Graphics Cards

If you’re going to run games, you need a video card. Everyone says the best cards are from Nvidia (Team Green), but Radeon (Team Red) gives them a run for their money. The current generation from Nvidia are the 30 series and they come in 1, 2, & 3 fan models. Yeah yeah, performance is good too, but if you’re going for small form factor, you need to take size into consideration. Three fan versions tend to be over 300mm, two fans tend to be over 220mm, and single fan GPUs are 170-190mm. So, if you want to go extreme SFF a single fan 3060 is what you need.

Installing the GPU is not the same as in a regular PC. Normally you just plug it into the keyboard and lock it down on the back panel. With SFF you don’t have room for that so you flip it around and put it back to back with the motherboard and connect it with an extension cable called a riser. Most SFF cases come with a riser, but you need to check which version of PCIe it supports. A PCIe 4.0 riser will run you about $70 and a PCIe 3.0 riser will run you about $30. It’s the price of doing business.

Note on need: You only need the high end cards for highly detailed, fast moving, newer games on large high resolution monitors. Strategy, simulation, and video playback don’t require as much beef. It’s ok to get used cards from previous generations if that’s not your bag. Just make sure you lookup the specifications for the games you wanna run. For machine learning Nvidia is the default card with CUDA cores.

Power Supply

Ya gotta power the thing right? First figure out how much power you need. I recommend using PCPartPicker to build your machine and it will tell you the wattage required. Always get more than you need. The PSU only produces the power asked of it and does best on a load 40-80%. So if it says you need 400 watts, get a 600w PSU. There are three main options for SFF power supplies:

• Just a SFX PSU – The most common power supplies (PSU) right now are SFX with cables coming out of them. They’re cheaper and that’s it. Make sure you get a good brand like Seasonic or Corsair.
• Modular SFX – This is where you start thinking about quality. You only attach the cables you need and they come with efficiency ratings. The more efficient, the less heat generated/wasted and the more likely it’s a good quality. Sidenote: You can buy custom cables in a variety of colors to spruce this up.
• Flex ATX – They are smaller (long and narrow) than SFX and they don’t come in modular versions. This specification was originally used for server rooms and not sold to consumers. As a result, they aren’t pretty and there are not a lot of options. The SFF community loves them so the options have improved more recently.

Make sure you get a power supply with its own fan. SFF cases don’t always have the best airflow so any extra help you can get is worth it.

Processor

You wouldn’t think the CPU matters, but it does. If it’s too overpowered, you will need better cooling. The smallest cases can barely handle cooling for an Intel i7 or Ryzen 7. An i5 or Ryzen 5 is a better option if you’re using a decent cooler. Team Red tends to run cooler overall. Also for the less experienced, it’s better to get onboard graphics so you can plug in a monitor to the motherboard if the GPU doesn’t fire right up. Pay attention to what socket your motherboard has, because that limits what you can plug into it. Gen 12 Intel cores don’t fit into a LGA1200 socket.

CPU Cooling

The only option for the smallest PCs (under 8L) is air cooling. There are a number of low-profile coolers on the market, but since you’re going SFF this is a really important decision worth paying a little extra for. Noctua makes the SFF CPU coolers. It’s a bunch of Austrians geeking out about fans and cooling. The NH-L9 series is so low profile that RGB ram can stick out farther from your board.

Liquid cooling is an option and it’s the best way to cool a more powerful system, but the radiators are usually the size of the bigger GPUs. Here’s what you should know:

• AIO – These are just what their name implies: All-In-One. There’s a CPU block that you bolt to the CPU socket on your board, it contains the reservoir and the pump. Two pre-attached pipes connect this to the radiator that gets rid of the heat. You usually need 2 big fans to push air through this.
• Full Liquid Cooling System – This is a big undertaking and really for the passionate high-end gamer who likes tinkering. Here are the parts:
  • Cooling Blocks: They attach to the points in the system you want to cool. You might have to buy a custom GPU that supports liquid cooling.
  • Pump: This moves the liquid and is often contained in the reservoir, but sometimes in the CPU block. If there’s air in your system, it won’t work well.
  • Radiator: There are a variety of sizes for these, but generally they’re the size of a large GPU. You can have more than one, but you need room for the 2-3 fans connected to them as well as good airflow in the case.
  • Pipes: You can have plastic, rubber, acrylic, transparent, translucent, opaque and connect them using compression fittings, press on fittings as well as putting dye in the liquid to light it up. Lot’s of planning and work here.

Storage

There are two types of storage: Active and Long-Term. Ram is active, hard drives are long-term.

Ram Modules

Depending on how many slots your motherboard has you should buy more than 1 memory module to take advantage of some read/write stuff. Your motherboard can only handle certain speeds and types of memory. Ram with RGB (LEDs) on them tend to be taller and some smaller cases can’t fit them.

How much ram? Windows requires 8-12 GB of ram depending on what things load when your start your computer up. Most other programs don’t need much. Games often can get by with 4-8 GB with the most resource intensive requiring 16. 32GB should handle anything out there, anything more is for running more things (ie. someone live streaming the game they’re on with multiple monitors and a chat).

Hard Drive Storage

Hard drives have made huge strides in speed and size. It used to be you’d mount a hard drive in your case, plug in a power cable from the PSU and a SATA cable to the Motherboard. Now we have M.2 SSDs that look like a small ram stick. Most motherboards now have M.2 slots on them.

How much storage? Depends on what your doing. Windows requires around 100GB and games vary, but the newest ones are coming out at 30-50GB per game. I like 1TB. It’s a good size for most people right now. Video editors will probably need an external RAID for long-term storage.

Operating System

Most likely you’re gonna want Windows. There are a lot of ways to do this:

1. Buy It – You can buy a license for Windows 11 from Microsoft for $139
2. Migrate It – I upgrade to a new laptop every couple of years for work. They come with Windows and all I need to do is grab the old hard drive and pop it in a new machine. I recommend pulling the License Key while it’s in the existing machine. I also recommend creating a restore disk.
3. Get it Used – Cheap old PCs are all over the place. Windows 10 came out in 2015. Can you find a 5 year old PC for free?

Example Builds

I should probably go through a few builds to show what you can do. If you want to play around with builds I recommend using PCPartPicker.com.

My Velka 3 Build

My goal was to put a gaming PC into the smallest case possible. After a lot of research, the Velka 3 is the only case I could find under 4 liters. So let’s build:

• Case: Velka 3 – $159.99 + $80 for the Gen4 PCIe Riser
• Power: ENP-7660B Flex 600w – $120 (bought from Velkase)
• Motherboard: Gigabyte Z590I AORUS ULTRA Mini ITX LGA1200 – $230 (eBay)
• CPU: Intel Core i7-11700K (onboard GPU) – $406 (direct)
• Cooling: Noctua NH-L9i chromax.black – $59.22 (NewEgg)
• GPU: PNY XLR8 GeForce RTX 3060 12GB (single fan) – $544.75 (eBay, during shortage)
• RAM: 2x16GB Corsair Vengeance DDR4-3000 CL16 – $137.99 (Amazon)
• Hard Drive: Samsung 970 EvoPlus 1TB M.2 PCIe3 NVME SSD – $99.99 (eBay)

Total price $1652.15 and I’ve since upgraded the Hard Drive to 2TB. It has a bit of trouble cooling an i7 at full bore, but the GPU and PSU are fine. You can also see it here: https://pcpartpicker.com/b/xfYH99

Budget SFF Build

If you’ve noticed, small parts can cost a lot. Especially when you’ve slapped the “gaming” label on it. Still, if you want to start a PC with cheaper components you can upgrade later, this is a passible build.

• Case: Densium 4 V2 – $160 + $10 for the Gen3 PCIe Riser (Densium)
• Power: ENP-7660B Flex 600w – $120 (Velkase) A good deal for 600w & 80+ Platinum.
• Motherboard: Gigabyte H610I DDR4 Mini ITX LGA1700 – $109 (NewEgg)
• CPU: Intel Core i3-12100F (no GPU) – $105.98 (Amazon)
• Cooling: Noctua NH-L9i – $45 (NewEgg) Pricey, I know. It’s the only one that’ll fit.
• GPU: GeForce 2060s & RX5600s are going for about $200 on eBay right now (Nov22).
• RAM: 2x8GB T-Create Expert DDR4-3200 – $43 (Amazon)
• Hard Drive: TeamGroup MP33 512GB – $34 (NewEgg) Get a cheap spinny drive for more storage.

Total price $820 give or take. If you get a slightly larger case you could fit a two fan GeForce 2060 or RX5600, but the price difference isn’t much. Remember, you do need a video card of some sort because there’s no on-board graphics for the CPU. You also could find a cheaper case, but most SFF cases are around $160 or more.

The RGB Special

This is what you come here for: Something Pretty. Let’s go crazy high end and build a baller SFF Gaming PC.

• Case: Densium 4 V2 – $160 + $10 for the Gen3 PCIe Riser (Densium)
• Power: ENP-7660B Flex 600w – $120 (Velkase) A good deal for 600w & 80+ Platinum.
• Motherboard: Gigabyte H610I DDR4 Mini ITX LGA1700 – $109 (NewEgg)
• CPU: Intel Core i3-12100F (no GPU) – $105.98 (Amazon)
• Cooling: Noctua NH-L9i – $45 (NewEgg) Pricey, I know. It’s the only one that’ll fit.
• GPU: GeForce 2060s & RX5600s are going for about $200 on eBay right now (Nov22).
• RAM: 2x8GB T-Create Expert DDR4-3200 – $43 (Amazon)
• Hard Drive: TeamGroup MP33 512GB – $34 (NewEgg) Get a cheap spinny drive for more storage.