Building your own PC can feel like stepping into a giant tech puzzle—so where do you start? Two of the most important choices are picking the right motherboard and matching it with the right power supply. But here’s the catch: the size of your motherboard doesn’t just decide what fits inside your case—it also affects how many parts you can install, how easy your build will be to upgrade, and even how your airflow works.
In this guide, we’ll break down the difference between ATX and MicroATX, compare their sizes, and explain how these decisions affect the overall layout of the computer parts. Whether you’re figuring out what you need to build a PC for the first time, upgrading your rig, or don’t even know what the meaning of ATX is, we’ll cover all the essentials to help you choose smartly. Let’s go!
What is ATX (Advanced Technology Extended)?
ATX, or Advanced Technology Extended, has been the gold standard since 1995. It’s the motherboard size most gamers, creators, and PC enthusiasts picture when thinking about a “full build.” Its larger footprint means more room for components, features, and flexibility, making it the foundation of countless gaming and workstation PCs.
Features and Size of ATX
A standard ATX board measures 12 x 9.6 inches (305 x 244 mm). It’s not the absolute biggest (that would be E-ATX), but it offers plenty of real estate to work with. Typical ATX motherboards include:
- Four RAM slots (sometimes supporting very high memory capacity)
- Up to seven PCIe (PCI Express) slots, including multiple full x16 slots for graphics cards
- Multiple SATA, USB, and at least one M.2 connector for SSDs
- Several system fan headers and often advanced features like thermistor headers
- Stronger VRM (power delivery), making them ideal for high-end CPUs and overclocking
- Wide choice of chipsets, from entry-level to flagship
Benefits of ATXs
The biggest advantage of ATX is breathing room. With more expansion slots, you can load your system with multiple graphics cards, capture cards, or even additional storage controllers. Its robust VRM designs make it the go-to for overclockers who want to squeeze every ounce of performance from high-end CPUs.
Cooling also becomes easier because there’s enough space to install large air coolers or custom liquid loops. Add to that a wide selection of cases and manufacturers, and ATX offers the most options for style, performance, and upgrade paths.
Drawbacks of ATXs
Of course, bigger isn’t always better. ATX requires mid-tower or full-tower cases, which means your PC will take up more space on your desk or floor and will likely weigh more, too.
Costs also add up: ATX boards themselves are pricier, and filling all those slots and ports can quickly stretch your budget.
And if you don’t actually use all the expansion options, much of that extra board space just sits empty, which can feel like wasted potential.
What is MicroATX (mATX)?
MicroATX, or mATX, is essentially ATX’s little sibling. By shaving off a couple of inches, it delivers a more compact option while still carrying the core features most builders actually use. It’s a favorite for budget builds or smaller cases without feeling too cramped.
Features and Size of mATX
MicroATX boards measure up to 9.6 x 9.6 inches (244 x 244 mm), though some models are slightly shorter (9.6 x 8.1 inches). They’re the same width as ATX but lose some length, which means fewer expansion slots, while still being compatible with ATX cases. Common features include:
- Up to four RAM slots (some boards only have two)
- Up to two PCIe x16 slots (sometimes fewer overall slots than ATX)
- Fewer USB, SATA, and M.2 ports compared to ATX
- Typically built on mid-range or entry-level chipsets
- Compatible with standard ATX power supplies
Benefits of mATXs
The charm of mATX is balance. You still get enough features for gaming, streaming, or productivity, but in a smaller, lighter, and more affordable package.
They’re especially appealing if you’re trying to save money, as mATX boards often cost significantly less than ATX while still handling modern games with ease.
Their smaller cases save desk space and make the system easier to move around, whether that’s to a LAN party or simply moving it to another room.
Drawbacks of mATXs
The compromise is expansion and flexibility. With fewer PCIe and RAM slots, your upgrade potential is more limited, especially if you dream of running multiple GPUs or massive memory kits.
Cooling potential also shrinks a little, as fitting large air towers or complex water loops into an mATX case can be tricky. And while the form factor is versatile, you’ll find fewer high-end options compared to ATX, both in motherboards and compatible cases.
For some, the smaller footprint is a plus, but in larger ATX cases, it can look awkward, with components crammed toward one corner.
What is Mini-ITX?
Mini-ITX is the champion of small form factor builds. Measuring under 7 inches square, it’s the choice for ultra-compact PCs, minimalist setups, or portable rigs you can carry under one arm. Despite its size, Mini-ITX has grown in popularity for high-end builds that prioritize style and portability.
Features and Size of Mini-ITX
Every Mini-ITX board is 6.7 x 6.7 inches (170 x 170 mm), very tiny compared to ATX and mATX. Common features include:
- Two RAM slots
- A single PCIe x16 slot
- One M.2 slot (sometimes placed on the back of the board)
- Very few SATA and USB ports
- Often supports high-end chipsets despite its small size
- May require smaller or proprietary power supplies
Benefits of Mini-ITXs
The obvious benefit is size. A Mini-ITX build can be incredibly compact, perfect for saving desk space or creating a portable powerhouse for gaming events or living room setups.
They also have a sleek, minimalist appeal, often paired with stylish small cases. And while expansion is limited, you can still run powerful CPUs and GPUs, sometimes rivaling ATX builds in raw performance.
For enthusiasts, they also offer better memory overclocking thanks to shorter trace lengths on the board.
Drawbacks of Mini-ITXs
But going small brings challenges. Mini-ITX boards are often more expensive than their size suggests, due to the engineering required to cram so much into a tiny board.
Building in these systems can be frustrating, with little room for cable management and strict cooler or GPU size limitations.
Cooling, in general, is harder, and components may run hotter in small cases. And with just one PCIe slot and two RAM slots, upgrade options are minimal.
ATX vs MicroATX vs Mini-ITX: Which Motherboard Specification to Choose
When choosing a motherboard for a PC build, the specifications of ATX, MicroATX, and Mini-ITX form factors present distinct trade-offs. Price, size, performance potential, connectivity, and upgradability all come into play. Understanding these differences is crucial to building a PC that aligns with your needs, budget, and the kind of system you want to create.
Price and Cost
ATX motherboards are usually more expensive than MicroATX, partly because of their larger size and richer feature sets. They can, however, be similar in price to Mini-ITX boards, which tend to cost more than you’d expect given their smaller footprint.
That’s because Mini-ITX requires more precise engineering and compact design, often making them as expensive as full-size ATX. MicroATX is the most budget-friendly option, both for the motherboard itself and for compatible cases, making it popular with cost-conscious builders.
Performance
ATX excels at performance thanks to its stronger power delivery and better cooling support, making it the top choice for overclocking or running demanding CPUs.
MicroATX boards can handle the same processors and GPUs as ATX, but they’re usually paired with mid-range chipsets, so extreme overclocking and very high-end builds are less common.
Mini-ITX can still deliver impressive performance, especially in gaming, but its smaller VRMs and cooling constraints make it less ideal for extreme processors or long-term heavy workloads.
Connectivity and Expansion
ATX motherboards give you the most expansion options, offering up to seven PCIe slots, four RAM slots, and multiple M.2 and SATA ports. mATX boards scale things down with fewer PCIe slots and slightly fewer ports, but still enough for most gaming or everyday builds.
Mini-ITX takes the most compact approach, with just one PCIe slot, two RAM slots, and limited connectors, making it best suited for small, minimalist setups where space matters more than expandability.
Upgradability
If you want a system that’s easy to upgrade in the future, go with an ATX motherboard. It offers the most flexibility, with room for multiple GPUs, extra RAM, and plenty of add-in cards or storage options. mATX gives you decent upgrade potential, but runs out of space faster once its slots are used. Mini-ITX is the least expandable, so you’ll need to plan your build carefully from the start since future upgrades will be limited.
Components to Use
ATX boards are best suited for high-end CPUs, multi-GPU setups, and advanced cooling systems, making them ideal for powerful workstations or gaming rigs.
MicroATX supports the same core CPUs and GPUs but usually limits you to a single graphics card and smaller cooling solutions, which is fine for most mid-range builds.
Mini-ITX often requires compact GPUs, low-profile coolers, and smaller or proprietary power supplies, though it can still house surprisingly powerful components in a very small package.
Recommended Uses
Whether you’re chasing top-tier performance, saving money, or squeezing serious power into a tiny case, each motherboard form factor has its sweet spot and suitable application.
ATX is the heavyweight champion, built for gamers and professionals who want maximum performance, cooling, and upgrade potential.
MicroATX hits the middle ground, offering plenty of muscle for gaming or office use without stretching your budget or hogging space.
And Mini-ITX is the sleek little powerhouse, perfect for anyone who loves compact, portable, or minimalist builds that still pack a punch. The choice comes down to your priorities: Do you want the biggest playground, the best balance, or the smallest footprint?
ATX vs MiroATX vs Mini-ITX: Board Comparison
| Factor | ATX | MicroATX (mATX) | Mini-ITX |
| Dimensions | 12″ x 9.6″ (305x244mm) | Max 9.6″ x 9.6″ (244x244mm) | 6.7″ x 6.7″ (170x170mm) |
| PC Sizes | Requires large/mid-tower cases | Fits compact cases; can fit ATX cases | Ultra-compact; smallest possible PC |
| Price/Cost | More expensive than mATX; similar to Mini-ITX | Cheapest form factor | Most expensive; similar to ATX |
| Performance | Best for overclocking, high-end CPUs; robust power design | Good for gaming, mid-range CPUs; lower cooling ceiling | Good for memory OC; challenging cooling for high-end |
| Connectivity | Most expansion slots (7), multiple PCIe x16, 4 RAM slots, many ports/headers | Fewer expansion slots (max 3 PCIe), up to 4 RAM slots, fewer ports | Fewest expansion slots (1 PCIe x16), 2 RAM slots, very few ports |
| Upgradability | Most flexible, extensive future upgrades | Limited upgrades compared to ATX | Most limited, challenging future upgrades |
| Components | Best for high-end CPUs, multiple GPUs, and custom cooling | Supports the same CPUs/GPUs as ATX, but fewer add-ons; less cooling potential | Low-power CPUs are common; specific CPU coolers are needed; high-end chipsets are available |
| Recommended Uses | High-end gaming, workstations, overclocking, multi-GPU, CPU-intensive tasks | Budget-friendly gaming, home/office, portable setups | Ultra-compact/portable PCs, HTPCs, minimalist builds |
FAQs
Which form (ATX or mATX) is better for gaming builds?
Both ATX and MicroATX can deliver excellent gaming performance since they support the same CPUs and GPUs. The main difference comes down to expandability and features. ATX is better if you want multiple graphics cards, more RAM slots, or stronger power delivery for overclocking. mATX, however, is often cheaper and perfectly capable for single-GPU gaming rigs.
Can I use a mATX motherboard in an ATX case?
Yes! ATX cases are backward compatible with smaller motherboards like mATX and even Mini-ITX. The only drawback is aesthetics, since your components may look bunched up in the top corner of a larger case, leaving extra space.
Is cooling/airflow better in ATX or mATX?
ATX generally has the edge here. Larger cases that fit ATX boards allow for more fans, radiators, and better airflow paths. mATX cases are smaller, which can limit airflow and cooler size, but modern designs still handle gaming components well. If you’re planning heavy overclocking or liquid cooling, ATX is the safer bet.
Which one consumes more power, ATX or mATX?
The form factor itself doesn’t determine power consumption. Power use depends on the CPU, GPU, and other components you install. That said, ATX boards often come with more features, like extra ports, slots, and stronger VRMs, that can draw slightly more power than simpler mATX boards. But the difference is usually minimal compared to the total system power draw.
Are there performance differences between ATX and mATX?
Not in raw gaming performance. Since both support the same processors and graphics cards, frame rates and computing power will be identical if you use the same hardware. Performance differences only show up in areas like overclocking potential, where ATX’s larger size allows for better cooling and power delivery.
Are there other motherboard sizes available?
Yes. Beyond ATX and mATX, there’s Mini-ITX, a tiny 6.7 x 6.7-inch board for compact builds, which we also discussed in the article. On the larger side, there’s E-ATX (Extended ATX), which is wider and often used for enthusiast-level workstations with multiple GPUs and lots of memory. There’s also XL-ATX in some high-end gaming systems, though it’s less common.
The Leading Brand for PC Cases—Okinos
No matter which motherboard you choose: ATX for maximum power, MicroATX for balance, or Mini-ITX for compact builds, the rest of your setup needs to match. A motherboard is the heart of your PC, but the case and accessories are what let it breathe, perform, and stand out. That’s when you find that having the right choice of PC case and cooling changes everything.
At Okinos, we believe every PC build should be more than just functional—it should be powerful, personal, and ready for the future. That’s why we create cases with precision engineering and builder-friendly innovation. From smart airflow layouts to tough materials and striking aesthetics, our gear transforms your setup into a true performance machine.
We offer a range of cases to suit every builder’s vision:
| # | Model | ITX | mATX | ATX | EATX |
| 1 | Air Cross | √ | √ | √ | X |
| 2 | Aqua 3 ARGB Black | √ | √ | X | X |
| 3 | Aqua 3 ARGB White | √ | √ | X | X |
| 4 | Aqua 3 Air Black | √ | √ | X | X |
| 5 | Aqua 7 Black | √ | √ | √ | X |
| 6 | Aqua 7 White | √ | √ | √ | X |
| 7 | Aqua 9 * | √ | √ | √ | X |
| 8 | Cypress 3 Wood | √ | √ | X | X |
| 9 | Cypress 3 ARGB | √ | √ | X | X |
| 10 | Cypress 5 Air | √ | √ | √ | X |
| 11 | Cypress 7 | √ | √ | √ | X |
| 12 | Mirage 4 Black | √ | √ | X | X |
| 13 | Mirage 4 White | √ | √ | X | X |
| 14 | Mirage 6 | √ | √ | √ | X |
We’re here for gamers, creators, and PC enthusiasts alike, whether you’re upgrading your rig, planning your first custom build, or sourcing bulk solutions. Reach out today and let us power your vision with hardware that blends reliability, innovation, and bold design in every build.
