Hi there! If you‘re embarking on building a new desktop PC, one of the most important choices is which motherboard to buy as the base. These system boards come in a variety of shapes and sizes known as form factors. And each best suits certain types of computers based on things like available space, budget, and needed capabilities.
In this epic guide, we‘ll take a tour through motherboard history and standards both new and old – from ancient AT style boards still powering Win 98 machines to bleeding edge E-ATX boards ready for next-gen gaming GPUs. You‘ll discover what sets apart a tiny Mini-ITX mobo from a server-grade SSI EE.
Let‘s dive in and explore the key differences across 7 major form factors still seen out in the wild today. I‘ll share plenty of examples plus helpful tips so you can decide what board standard fits your PC build best!
What Is A Motherboard?
A motherboard, also known as a mainboard or logic board, is the primary printed circuit board (PCB) in any personal computer that houses critical components like the central processing unit (CPU), memory, integrated peripherals, expansion slots, etc. It provides electrical connectivity and data routing to tie these attached devices together allowing them to communicate and function in unison.
Without a motherboard it would be game over for your PC before it even began! Modern motherboards contain embedded controllers, bus logic, voltage regulators, capacitors, firmware chips and much more. Together these elements supply power management and data access coordination so all the pieces can work in harmony.
A labeled diagram of a typical ATX motherboard [Image Source: MyCplus via Wikimedia Commons]
While laptops, smartphones and tablets now dominate personal computing landscape, traditional desktop PCs live on and remain a strong choice for tasks demanding top performance like gaming, media production, scientific computing and software development.
These desktops in all their shapes and sizes have motherboards at their foundation. Understanding this critical component will give you insight into building, upgrading or buying PCs.
So let‘s explore how motherboards have evolved over computer history and the essential form factors you need to know when configuring your own rig…
The Evolution of Motherboard Standards
Motherboards and their electrical standards have closely tracked developments in computer processors and memory technology over the last 40+ years. The goal has always been balancing space constraints with thermal concerns and performance capabilities.
The Early Days
In computers of the 70s and early 80s, system boards were largely one-off custom designs since applications and use cases varied so greatly. But a huge shift began when IBM introduced the ISA bus standard in 1981 for its revolutionary IBM Personal Computer.
While primitive by today‘s measure, the original IBM PC motherboard (known as the planar) brought openness and standardization that proved a huge catalyst for innovation. Soon many companies began cloning and enhancing IBM‘s design.
By the mid 80s, size constraints around using lots of expansion cards led to the popularization of the AT (Advanced Techology) standard as a replacement to the aging ISA specification. AT brought 16-bit capability allowing much faster data transfers compared to 8-bit ISA.
AT motherboards became ubiquitous driving millions of MS-DOS and early Windows PCs well into the 90s. It was in many ways the workhorse that laid foundation for the standardized high-performance desktop.
The 90s PC Explosion
Demand for more multimedia capabilities and portability led to the first widely adopted smaller variant known as Baby-AT in the early 90s. But soon its own limitations around coping with the needs of advancing CPUs and graphics adapters necessitated a new generation of board.
Thus, Intel delivered the ATX form factor in 1995 to become the new standard that still dominates desktop computing today. Bringing integrated I/O, power supply signaling, and improved width/depth balance, ATX delivered needed headroom for the Pentium CPU revolution in an increasingly compact form.
Variants like micro-ATX quickly followed to cater to smaller computers. The late 90s explosion around desktop productivity and gaming pushed motherboard tech forward at a blazing pace. More integrated functions eventually paved way for smaller boards.
7 Essential Form Factors To Know
Now that you know how we arrived at today‘s landscape let‘s jump into detail on 7 board specs that still see action in everything from mission critical data centers to dorm room gaming battlestations and embedded industrial controllers!
1. Mini ITX
Don‘t let the tiny size fool you – Mini ITX packs a punch! Ranging under 7 inches square (hence the ITX designation), Mini ITX originated from VIA Technologies around 2001 to cater to digital signage, car PCs and embedded controls.
This bite-sized form factor has caught on big time in recent years among home theater PC builders, backpack VR rig builders, and budget gamers. The compact design means limited expansion capability – normally a single PCIe x16 slot for graphics and a modest number of onboard SATA ports and DIMM slots.
But with beefy APU processor graphics and M.2 SSD storage options luxury of expansion becomes less important. What you trade in capabilities you get back in teeny footprint. And it opens fun case modding possibilities!
With abundant high density Mini ITX board choices like ASRock‘sDeskMini line they‘ve become especially popular to power compact, powerful living room gaming and media rigs. Paired with a Steam Deck for the ultimate mini battle station!
Ideal User: Space-constrained gamer, media box builder
2. Micro ATX
Following the success of ATX for standard tower builds, the microATX take aimed to condense expansion capability for space-limited home and office desktops. Introduced in the late 90s these boards squeeze full I/O and capable CPU/RAM support into a smaller mid-tower friendly package.
Today‘s microATX boards share everything like NVMe SSD and PCIe Gen 4 support found in their full-sized ATX counterparts. Just condensed into a more confined footprint ranging under 10-inches square. Close quarters also necessitate creative cooling solutions as airflow is restricted.
Most boards sport 2-4 DIMM slots, 4-6 SATA ports, a full length PCIe x16 slot or two, and all expected modern connectivity like USB/Thunderbolt. More compact for sure but very much potent!
Micro ATX enjoys massive adoption among DIY system builders and OEM machines like Dell‘s XPS series. Given the minimal compromise compared to standard ATX, also makes a great frugal starting point for novice PC builders.
Choices like MSI‘s B550M PRO-VDH WIFI have all you need for a capable 1080p or even entry 4K gaming rig without breaking bank or space requirements!
Ideal User: Mainstream gaming, general use
Example of a Micro ATX board with GPU installed [Image Source: Wikimedia Commons]
3. ATX
9 out of 10 desktop PCs you‘ll encounter are likely built around a standard ATX motherboard. Since its introduction succeeding the original AT form factor in 1995, ATX has proven tremendously successful as an open standard. The 12 x 9.6-inch max size boards strike a balance suitable for nearly any tower build.
Modern ATX boards offer the very latest – DDR5 RAM, blistering PCIe 5.0 GPU slots, NVMe Gen 4 storage support, WiFi 6E, Thunderbolt 4 and every bell and whistle you could ask. Choose between AMD‘s precision boosting AM5 and Intel‘s unlocked K-SKU CPUs to build a productivity or gaming monster!
And you aren‘t at all limited on expansion capabilities like some smaller boards. Seven or more PCIe slots are common to enable multi-GPU setups for hardcore gaming or AI development. Massive E-ATX tower cases have the room to install intricate liquid cooling solutions to push overclocks further.
The ATX standard has aged incredibly well – being suitable as foundation everything from budget office PCs to extreme performance workstation builds. And expect ongoing support for years with future CPU and memory spec updates centered around ATX boards.
Among virtually endless ATX options the Asus TUF Gaming X670E-Plus offers a stellar blend of next-gen power for the money. Ready to house AMD‘s fastest Ryzen 7950X CPU plus capable PCIe Gen 5 graphics!
Ideal User: Enthusiast DIY builder, high FPS gamer
4. XL-ATX, HPTX and Beyond!
Think ATX sounds big already? It can get much, much bigger my friends! Let‘s touch on Extended ATX then dive deep on the ultra exotic stuff.
E-ATX or Extended ATX simply builds on standard ATX by increasing width from 9.6 up to 12 inches. The extra real estate allows packing in a whopping 7-8 PCIe expansion slots to create the ultimate GPU compute or storage server powerhouses! Of course you need an equally giant enclosure to make use of the full footprint. These are right at home in rackmounted sever builds and giant design workstations.
XL-ATX takes expansion potential even further ballooning out width up to a cavernous 13.6 inches! Now were talking serious business for heavily loaded database servers and animation render clusters. CEB and EBX are two proprietary server-focused standards also designed around XL-ATX width spec but with differences in board shaping and mounting.
HPTX motherboards take the high-roller excess train to a whole other level! How does nearly 20-inches wide and 15-inches deep sound? Introduced by Asus in 2011 to power extreme gaming systems, boards like the Maximus V Extreme live up to the promise. Each of the mammoth eight PCIe x16 slots gets its own full-speed 16 lane PCI Express 3.0 pipeline straight from the CPU. Take that punyXL-ATX!
With quad SLI/CrossfireX potential and slots galore for RAID cards HPTX builds stand in an elite class only the most insane enthusiasts can justify! But oh what a marvel to behold for the rest of us mere mortals.
Clearly not many can claim genuine need for anything exceeding extended ATX girth. But isn‘t it fun to see how outrageous things can get on the cutting edge?!
5. Mini-DTX
Let‘s get back down to Earth now with mini-DTX – essentially a modern standard intended to replace outdated small boards like Mini-ITX. Defined in 2001 by the Desktop Form Factor Working Group these compact boards measure under 8 x 7 inches but still manage to cram the peripheral connectivity and expansion capabilities found in their larger Micro-ATX kin.
You can expect integrated sound/video outputs, WiFi, at least two full-sized PCIe x16 slots plus a half-height slot as well. So mini-DTX delivers ATX-class expansion condense right down into spaces better suited to mini-ITX. The catch being chassis and cooling concerns. Their niche is industry applications like digital signage needing I/O density over sheer compute power.
So far mini-DTX has gained modest but growing adoption in specialized verticals. For instance HP deploys them in compact business PCs like the ProDesk 600 G6. Compared to the older standards they aim to replace, the future looks bright for mini-DTX making further inroads among space-constrained workstations.
6. Thin Mini-ITX
A Thin Mini-ITX Board from ASRock [Image Source: ASRock]
Take mini-ITX and plays limbo – how low can you go? Thin Mini-ITX (or mini-STX) breaks out the slide rule to squeeze width down to an incredible 5 inches or less. Introduced more recently by Intel these highly compact boards cater to slim small form factor chassis and fanless designs prevalent in office machines, industrial controllers and panel PCs.
Despite shedding width they slim boards like ASRock‘s X300TM-ITX pack impressive capability including DDR4 SO-DIMM slots, M.2 PCIe NVME storage and Outputs for dual displays. Low power mobile CPUs allow effective fanless passive cooling while embedded IoT models offer wireless plus ruggedization. All great features but lidless boxes need not apply here!
Ideal User: Industrial control, corporate IT admins
7. NLX
NLX hit the scene around Y2K with a specific goal: Deliver workstation-class performance for applications like audio production absolutely silently courtesy of optimized passive cooling.
While roughly adhering to ATX spatial specs, these noiseless computing boards introduced tweaks targeting thermals and acoustics. Elements like spreading components across zones, separation bars, directed airflow ducting and noise dampening materiels took priority over expandability.
Cooler Master, Antec and Zalman all shipped well-received near silent systems leveraging NLX boards. And while the standard didn‘t set mainstream market ablaze it did gain traction in recording studios and home theaters where noise floors rule. Fan stop options make today‘s rigs far quieter, but for a time NLX delivered the ultimate hush.
Ideal User: Audio engineers, custom home theater builders
Relative size comparison of common motherboard form factors [Image credit: Wikimedia Commons]
Choosing What‘s Right For You
With this whirlwind tour of motherboard standards now under your belt, let‘s discuss how to decide what‘s right for your next PC build or upgrade.
Ask yourself a few key questions:
- What sized computer case makes sense – mini, mid or full tower?
- Will you run multiple GPUs or just one?
- How much expansion capacity is needed?
- Any noise constraints to consider?
- What‘s my maximum budget?
If rocking a single powerful video card in a compact mid-tower case sounds like the plan then microATX is a splendid match. Prefer stuffing tons of HDDs and PCIe cards into a server rack? E-ATX or XL-ATX has you covered. Building a living room media box? Check out mini-ITX. Other questions just drop them in the comments!
No matter the job understanding the landscape of motherboard form factors helps narrow the options. Once size and basic specs are decided you can zero in on specialized features like overclocking potential, ports needed, and processor support to find your perfect match.
Here‘s to happy motherboard hunting and maybe I‘ll catch you online with our compact creations someday! Let the PC gaming commence 😁
