EATX Motherboard is a motherboard that measures 12" x 13", the same size as an ATX motherboard. It's more often called EATX on store pages, but some manufacturers are calling it Extended ATX (E-ATX) instead, which isn't exactly right because E-ATX denotes motherboards that use the EATX form factor but have a different width and height. The correct term is just EATX, period.

Why Is It Called EATX Motherboard?

EATX motherboard was originally introduced in 1997 by Intel with their Pentium Pro series of processors. Back then most motherboards were based on the Baby AT (also known as BTX) form factor which simply denotes a motherboard that uses a 3.6" x 4.8" board, however, Intel realized at the time that computers are evolving beyond what can be defined by these two dimensions alone because there are things like AGP video cards changing shape, CPUs generating more heat, graphics cards drawing more watts, etc. This is why they came up with the EATX board so they can accommodate motherboards of different sizes with extra room for expansion slots, larger components, etc.


EATX Pros and Cons

If you have a lot of money and want the best performance, EATX motherboards provide several benefits over ATX motherboards. Plus, keep an eye on the drawbacks to make your selection.


  • It has a massive amount of space to install the memory.
  • More expansion port means more GPUs, hence a better gaming experience.
  • The large size of the board cools the components and offers fantastic overclocking.


  • It requires a heavy budget.
  • EATX is not suitable for hobbyist gamers or editors unless you have a lot of money.
  • Their large size and features can be a bit overkill for many users.

ATX VS EATX: Functionality

The following table shows the differences between ATX, Extended ATX (EATX), and SSI EEB in terms of physical dimensions.
Feature Standard ATX Extended ATX (a.k.a EATX) SSI EEB Dimensions 12" x 9.6" 12" x 13" 13" x 15" 12.4" x 10.2" Power Pin Count 24 24 20 20 VRM 8+2 or 6+2 8+2 8+3 8+3 Front Panel Connector USB 2.0 Type A USB 2.0 Type A None USB 3.0 Type A None USB 3.0 Type B Ethernet RJ45 Ethernet RJ45 Ethernet RJ45 Ethernet45 SATA 6Gb/s 4 6 10 12 SATA 3Gb/s 8 8 8 8 PATA 2 2 2 0 PCI-e 16x 3 16x 4 16x 4 18x+ [1] [2] [3] [4] [5] PCI-e 1x 2 1 0 0 0 ISA None None None None


SSI EEB is a new form factor, which was introduced in 2011 by Intel. It's targeted at the high power computing market and EATX is an offspring of SSI EEB.


The sort of motherboard you choose is determined by your requirements. If you are a serious competitive player, for example, you'll need a powerful PC system with dual graphics cards and superior cooling, which necessitates a larger motherboard (EATX). However, if you're simply a hobbyist gamer, an ATX or smaller motherboard should be enough. The choice is yours.