For PC builders creating their dream custom gaming or workstation rig, choosing the right motherboard is foundational. Two of the most popular options include the widely used ATX form factor, and its bigger sibling – EATX.
But what exactly is the difference between these two standards, and how do you decide which one fits your needs?
In this comprehensive guide, we’ll unpack everything you need to know comparing EATX and ATX motherboards.
What Are EATX and ATX Motherboard Standards?
First, let‘s quickly define these two common motherboard formats.
ATX
The ATX (Advanced Technology eXtended) standard was introduced by Intel in 1995 to replace older form factors and create a unified motherboard design usable across different PC configurations.
Over subsequent revisions, ATX has become the most popular motherboard platform used in the vast majority of desktop PCs from mass market pre-builts to DIY custom builds.
EATX
EATX (Extended ATX) motherboards build on the ATX standard with a larger printed circuit board (PCB) to enable packing in more features and connectivity.
The “Extended” delineation gives a strong hint into how EATX boards differ from traditional ATX. The expanded dimensions allow manufacturers to cram in more technology!
Now that we understand EATX and ATX basics, let’s do a deep dive on how they compare.
Dimensional Differences
The most obvious distinction when looking at an ATX board next to an EATX is the sheer physical size.
ATX Dimensions
ATX motherboards strictly adhere to standardized sizing with dimensions of 12 inches x 9.5 inches (305mm x 244mm).
This provides a large enough footprint suitable for a full sized desktop PC build, while still optimizing PCB space and costs.
EATX Dimensions
Due to their extended PCB, EATX motherboards measure a much roomier 12 inches x 13 inches (305mm x 330mm).
That’s close to 26% more surface area than traditional ATX! This has direct implications on layout and expansion capabilities…
Expansion & Layout Comparison
The expanded dimensions really give EATX boards an edge when it comes to features and connectivity.
Let‘s compare ATX and EATX across some key motherboard specs:
| ATX | EATX | |
| DIMM Slots | 2 – 4 | Up to 8 |
| PCIe x16 Slots | 1 – 3 | Up to 4 |
| M.2 Sockets | 1 – 2 | Up to 4 |
| SATA Ports | 4 – 8 | 8+ |
| Fan Headers | 4 – 6 | 6+ |
As you can see, EATX uniformly provides more of every critical motherboard feature category.
More Bays
The extra PCB real estate leaves room for additional component bays and connectors:
- PCIe x16 – Enable installing more graphics cards
- M.2 Sockets – Support faster NVMe SSDs
- SATA – Connect more HDDs and SATA SSDs
- DIMM – Accommodate larger, higher performance RAM kits
Improved Cooling
EATX boards also excel when it comes to cooling capacity:
- Abundant fan headers (6+) to power multiple case fans
- Increased headers for all-in-one liquid CPU coolers
- Bigger PCB allows for better airflow across board
In summary, if you need abundant expansion capability – EATX delivers!
Performance Impact of Added Features
Now you may be wondering – how do these plentiful extra features actually impact real world performance?
Let‘s analyze a few examples:
Faster SSD Speeds
Take M.2 NVMe solid state drives which offer blazing transfer speeds exceeding 3500 MB/s.
Most ATX boards include 1-2 M.2 sockets, limiting NVMe SSD configurability.
Meanwhile high-end EATX boards like the Asus ROG Zenith II Extreme host four M.2 slots, enabling creating blistering fast RAID 0 arrays.
Unleashing Multiple GPUs
Gamers and creators running intensive 3D applications can reap huge performance benefits scaling up GPU horsepower.
ATX boards generally provide 2-3 PCIe x16 slots which is ample room for a dual graphics card setup.
EATX options like Gigabyte‘s X399 AORUS Xtreme pack four PCIe x16 slots, ready for quad SLI or CrossfireX multi-GPU action!
According to testing by Tom‘s Hardware, combining two GTX 1080 Tis in SLI can provide up to 95% improved rendering speeds in supported titles @ 4K resolution.
So if you demand no-compromise frame rates, only an EATX board has the expandability to fully unlock multiple monster GPUs.
Supercharged Memory Performance
Finally, the abundance of DIMM slots on EATX boards supports building extremely high capacity RAM configurations.
Mainstream ATX options top out around 128GB (4x 32GB sticks) which easily satisfies typical workloads.
However, moving up to an EATX board like Asus‘ Zenith II Extreme lets you max out at a gargantuan 256GB (8x 32GB) system memory!
This amount of RAM becomes important for RAM drive caches, virtualization uses, large database servers, and memory-intensive HPC workloads.
Benchmarks at tech sites like AnandTech demonstrate how such high capacity memory configurations provide performance benefits in optimized applications.
So if you have extreme memory bandwidth demands, EATX delivers the DIMM slots to satisfy.
Power Delivery & Overclocking Comparison
When building cutting edge rigs for gaming or productivity, many PC enthusiasts turn to overclocking to eke out extra performance.
How do EATX and ATX motherboard power delivery subsystems and overclocking support compare?
Power Phases
The voltage regulator module (VRM) on your motherboard supplies stable, clean power to the CPU along with protection circuitry.
Higher phase power designs provide rock solid stability when overclocking multi-core CPUs at extreme speeds.
For example Gigabyte‘s Z690 AORUS Xtreme EATX board sports an insane 20+1+2 digital VRM phase array to drive next-gen Intel CPUs like the 12900K.
Compare this to a decent MSI Pro Z690-A ATX board with a 14+1+1 phase VRM.
Clearly the premium EATX option offers advantages pushing overclocks thanks to advanced cooling and more phase balancing.
Extreme Cooling Connectivity
In addition, top tier EATX boards offer many fan control and liquid cooling features for keeping thermals in check during aggressive OC runs including:
- Multiple water cooling temperature header sensor inputs
- 10+ fan control headers
- Exact PCB cutouts to allow integrating complex liquid cooling plumbing
Without robust cooling, extreme overclocks leading to CPU or GPU thermal throttling under load.
Price Comparison
Of course this abundance of premium features and overclocking muscle does come at an increased price.
Due to additional PCB layers, high quality components, and more integrated I/O, EATX motherboards cost substantially more than ATX alternatives.
Let‘s compare boards with roughly equivalent features:
- Gigabyte Z690 AORUS Elite AX (ATX) – $260
- Gigabyte Z690 AORUS Pro (EATX) – $360
As you can see, stepping up to the EATX variant commands a nearly 40% price premium!
And that delta increases further when looking at the top shelf enthusiast segment:
- Asus ROG Maximus Z690 Hero (ATX) – $599
- Asus ROG Maximus Z690 Extreme Glacial (EATX) – $1,799!
So why does stretching to an extended ATX board cost so much more?
Why EATX is More Expensive
There are a few reasons why EATX boards demand steeper pricing:
More Complex PCB
Accommodating vastly more layers and connectivity requires a denser, more intricate printed circuit board costing more to produce.
Additional Components
Higher phase power delivery systems utilizing premium DrMOS and quality chokes + capacitors is also a cost adder.
Low Volume Production
With the majority of desktop builds centered around standard ATX boards, EATX models are produced in lower quantities. This results in higher per unit costs.
Advanced Features
Packing in more advanced functionality like onboard overclocking LCD displays, 10GbE networking, exotic cooling mechanisms – also raises the BOM cost.
Brand Tax
Finally, top enthusiast brands like Asus ROG and Aorus leverage their halo reputation to command higher pricing for their premium EATX offerings.
So while the bigger board size and abundance of connectivity does enable next-level desktop performance, be prepared to shell out more compared to ATX.
EATX vs ATX: Pros and Cons
Now that we‘ve explored how EATX and ATX compare across a range of criteria, let‘s summarize the relative pros and cons of each form factor:
ATX Motherboard Pros
- Less expensive for similar feature sets
- Fits all standard ATX computer cases
- Provides good balance of expansion capability
- Available from all major motherboard brands
ATX Motherboard Cons
- Limited to 3 or less PCIe x16 slots
- Typically only supports 2 RAM modules per channel
- Restricted to 1-2 M.2 NVMe SSD sockets
EATX Motherboard Pros
- Supports multiple graphics cards (up to 4 way SLI/CrossfireX)
- Capacity for massive RAM configurations (up to 256GB+)
- Many more SATA ports for huge storage arrays
- Added USB/SATA/Fan connectivity
EATX Motherboard Cons
- Significantly higher cost over ATX
- Requires expensive EATX full tower chassis
- Overkill expansion for most mainstream PC builds
- Low availability – niche enthusiast product
So in summary, while ATX boards strike the ideal balance for the majority of use cases, EATX unlocks almost unlimited expansion flexibility for maxed out workstations.
Bottom Line
Comparing EATX vs. ATX motherboards yields some clear distinctions.
While EATX options cost considerably more, you gain tremendously increased capability to create no-compromise elite rigs whether for gaming, video production or 3D modeling.
However, for general desktop needs, or situations like budget gaming system builds, standard ATX boards feature well-rounded expansion at reasonable price points.
So carefully analyze your desktop expansion requirements, performance goals and budget considerations when deciding between standard or extended ATX boards.
Hopefully this deep dive dispels any confusion differentiating these two popular motherboard form factors. Now you can make an informed choice picking EATX or ATX foundations ultimate custom PC!
