Intel decided what motherboards look like in 1995, and we're still living with the consequences

Published Nov 3, 2026, 11:30 AM EST Ever since he got his first smartphone, the legendary Nokia 6600, back in 2005, Goran became obsessed with technology. This obsession had only gotten worse after he received his first gaming PC a couple of months later. He fell in love with video games in the early '90s, shortly after embarking on his gaming journey with the Sega Master System II and SNES. Since then, he has built dozens of PCs, played thousands of games, and authored hundreds of articles about PC hardware, gaming hardware, and video games. He knows everything there is to know about the PC gaming and PC hardware space, and while his console gaming knowledge isn't as comprehensive, he considers himself a console veteran. Goran has almost a decade of experience writing about tech and video games for numerous web publications including TechSpot, TechPowerUp, and EsportsHeadlines. He has been writing for How-To Geek since December 2022. When he isn't gaming or deciding which component of his PC to upgrade next, you can find him strolling around Novi Sad while listening to music and contemplating what to play next. Sign in to your How-To Geek account If you’re rocking a desktop PC, there’s a good chance the motherboard it’s built around is based on the ATX (Advanced Technology Extended) or mATX standard, the latter being basically a shorter ATX board. Sure, there are SFF PC fans out there, but no other motherboard form factor comes close to the popularity of ATX, and we have Intel to thank for coming up with the design found in countless PC cases around the world. While ATX is one of the biggest success stories in PC hardware, its mid-1990s design is starting to show its age. Despite its shortcomings, chances are the most important elements of ATX will live on for years to come because, right now, nothing else can match the pragmatic genius of ATX. Before Intel's push, IBM's AT and Baby AT were the standards home PC motherboards followed But they were getting behind the times Credit: Rmyers7/Wikimedia Commons The pre-ATX era was dominated by two standards pioneered by IBM. Unlike Intel, IBM didn’t really plan to make its AT (Advanced Technology) motherboard form factor the standard in the PC market. However, because IBM PCs based on AT motherboards were so popular and IBM published detailed specs for the standard, many companies that produced IBM PC clones followed the AT to a T. That way, PC builders of the era could upgrade to faster CPUs with new motherboards that would fit the cases they were already using. After IBM released the first PC based on the AT motherboard in 1984, clone board makers soon embraced the form factor, and just a few years later, everyone was rocking AT boards in their PCs. But the AT form factor had a major caveat: it was simply too large. While it had room for eight expansion cards, its size made it incompatible with the increasingly popular smaller desktop cases of the time. Besides, even in larger cases, the AT would end up sitting behind the drive bays, blocking them and making installing new drives a proper pain. Credit: Anabase / Wikimedia Commons IBM shrank its AT design to fit its smaller XT case, more or less accidentally creating a new form factor that came to be known as Baby AT. These boards were smaller, allowing them to fit more compact cases; they caused far fewer issues with drive bays, and within a few years of their introduction in the mid-1980s, they became the most popular motherboard design in home PCs. Despite their popularity, Baby AT boards came with a number of shortcomings. For instance, the only I/O port soldered directly to the board was a single keyboard connector. The rest of the ports had to be connected with ribbon cables. As more ports moved onto the board (first serial and parallel ports, then USB), these boards turned into rat’s nests of ribbon cables, which made installing and adding more ports a chore. Credit: Anabase / Wikimedia Commons With the arrival of Pentium CPUs, which required large passive and active heatsinks, along with the rise of longer 72-pin SIMM (single in-line memory module) memory that replaced short 30-pin SIMMs by the mid-1990s (and later DIMMs), Baby AT board design proved to be inadequate because heatsinks and memory modules would block expansion card slots and drive bays, hindering upgradability. Baby AT boards had a few other shortcomings, such as two nearly identical power connectors that could fry the board if plugged in the wrong way, and the inability to shut the PC down via software. Intel designed ATX for its Pentium-era PCs And ATX caught on due to Intel's dominance in the CPU and motherboard markets Credit: theretroweb.com Baby AT’s limitations led Intel, which was by far the largest CPU and motherboard maker in the world at the time (everyone growing up in the 1990s knew about Pentium CPUs), to come up with the ATX motherboard form factor. The company needed a new motherboard platform for its Pentium-era PCs, and the goal was to create a new standard that would allow easy expansion, be relatively cheap to make, offer better connectivity support than older standards, and work with current and future CPUs. ATX was the answer, and it did more than a few things right. For starters, ATX was free and open to implement, which, along with Intel’s dominance in the home PC CPU, motherboard, and chipset space, drove its rapid adoption. Taiwanese motherboard vendors mostly made boards for Intel CPUs, and since the standard was free, they quickly followed Intel in embracing ATX. The ATX layout was also a well-thought-out design. By rotating the Baby AT layout 90 degrees, Intel placed the CPU next to the power supply and away from the expansion slots, preventing the CPU or memory from blocking add-on cards. Intel placed the main 20-pin Molex plug at the top of the board because cases of the time featured PSUs above the motherboard, and the plug was keyed so you couldn’t plug it in wrong and fry the board. Storage drive connectors were placed close to the drive bays (back then, cases had 5.25-inch and 3.5-inch drive bays at the front), and the design allowed the PC to turn off via software or a power button. The two most important ATX layout elements, though, were the rear I/O panel and the expansion-slot layout. The former included ports that were soldered directly to the board, so no cables were needed. The panel also didn’t have a fixed port layout, allowing board makers to include any ports they wanted, which proved important for ATX’s longevity. The latter included space for seven expansion card slots, which proved beneficial as GPUs grew in size, and allowed any expansion standard to be implemented. After its release, ATX took the world of home PCs by storm. Intel released the mATX variation of the layout in 1997, which also proved quite popular. By the end of the 1990s, Baby AT was largely abandoned, ATX alternatives proved anything but successful, and ATX had become the standard for the majority of PC motherboards. More than 30 years later, the flexible design is what's keeping ATX as popular as ever Unlike IBM's designs, ATX has kept up with the times While some large OEM PC brands, such as Dell and HP, have long used proprietary motherboard designs, many of these designs borrow heavily from ATX. In the DIY market, ATX is king, with its shorter variant, mATX, offering a more compact option. The only motherboard form factor that can come close to it is Mini-ITX, developed by VIA in 2001. While ITX boards are the go-to choice for small form factor builds, they aren’t nearly as widespread as ATX, and they too follow the most important ATX features, such as the rear I/O panel location, mounting holes, and power connectors. The reason ATX boards are as popular as they were decades ago is the layout’s flexible design, which covers just a few of the most important specs: dimensions, mounting holes, the location of the I/O panel, the max number of expansion slots, and the type of onboard power connectors, which is the part of the ATX specification that has evolved the most since its inception. Credit: MSI Vendors can freely choose the number and type of expansion slots (motherboards went from ISA to PCI and AGP, then to PCIe), the CPU socket, memory modules, storage drive ports, internal headers, chipsets, connectivity ports on the rear I/O, and more. A good example is the recently developed CAMM2 memory standard, with some vendors working on regular ATX motherboards that use CAMM2 modules instead of DIMM slots, which shows just how versatile and adaptable the ATX design is. Due to ATX’s lean specs, plenty of PCB real estate, and the constant shrinking and integration of various chips and controllers into the CPU and chipset, modern boards can pack beefy CPU VRMs, M.2 slots that support speedy NVMe drives, PCIe expansion slots, 40Gbps USB-C ports on the rear I/O, a wealth of fan headers, and integrated audio on a motherboard that has the same form factor as those that came out three decades ago. For the same reason, the ATX layout will continue to be the best choice for the foreseeable future. Some ATX design choices are showing their age, especially when it comes to GPUs The future might bring improvements, but ATX will likely live on Not all’s perfect in the ATX house, though. For instance, while seven expansion slots were fine for decades, the growth spurt of gaming GPUs, some of which now take up four expansion slots, means modern motherboards have fewer add-on card slots than before. Due to their weight, GPU sag is also becoming a real issue, with many graphics cards coming with support brackets — for example, my Sapphire Pulse RX 9070 XT comes with one, as you can see below. There’s also the issue of the M.2 slots. Some boards offer upwards of five M.2 slots, but the main one sits right above the GPU slot to keep it close to the CPU and preserve signal integrity, which means that once you install a graphics card, it covers the SSD. The rest are often placed between the PCIe slots, right under the GPU. This can lead to toasty NVMe SSDs that sometimes require heatsinks to keep their thermals in check. Credit: ASUS ATX boards have also been suffering from a cable mess thanks to the many internal headers (USB, fan, audio, and front panel headers) found on every modern motherboard. The situation with power connectors is also less than ideal. The CPU power connectors at the top of the board are a remnant of the times when PSUs were at the top of the case, making modern PC building harder than it needs to be, and the power connectors are also too big, especially the 24-pin one. While Intel has been trying to replace the 24-pin connector with a smaller 10-pin connector that's part of the ATX12VO standard, the change hasn’t gained traction outside some OEM PCs. More recently, Intel released the ATX12VO V3 spec with an even smaller 8-pin connector, but it’s still early days, and it’s uncertain whether motherboard and PSU vendors will embrace it anytime soon. ASUS (BTF), MSI (Project Zero), and Gigabyte (Project Stealth) have been trying to solve the cable issue with designs that move connectors to the rear of the board, but since there’s no universal standard (like ATX was back in the day), these back-connect boards remain a niche, with just a handful of models and compatible cases. As it looks right now, the majority of PC motherboards will continue to use the ATX standard along with the flaws and limitations that come with it. ATX has its flaws, but it's one of the most successful standards ever Despite being anything but perfect, ATX is still by far the most popular desktop PC motherboard standard, with no real competitor outside of the SFF space. Intel itself tried to replace it with BTX, but it never caught on, and Intel’s other layouts, like NLX for slim PCs and WTX for workstations, didn’t fare any better. AMD also tried to promote its own DTX and Mini-DTX layouts, but they’re almost nowhere to be seen. We also had a few oversized takes on ATX (XL-ATX, HPTX), but those, too, haven’t moved the needle. ATX still reigns supreme, and until the march of progress deems it incompatible with some future CPU, GPU, or technology that becomes essential for desktop PCs, you’ll continue building your desktops around an ATX or an mATX motherboard, unless you opt for an SFF machine.