E-ATX mounting vs ATX

Windfall

SFF Guru
Original poster
Nov 14, 2017
1,498
1,175
Looking to design a slim E-ATX case, but I'm unable to find certain specs and what it does/doesn't share with ATX, as well as the other mounting points.

I've been looking through the ATX specs and Wikipedia of all places, but to no avail.
 

Solo

Master of Cramming
Nov 18, 2017
521
931
Idk buy some cheap ass case and board and figure it out
 

Windfall

SFF Guru
Original poster
Nov 14, 2017
1,498
1,175
Idk buy some cheap ass case and board and figure it out
Thanks for your help.

10/10 for Technical Info
10/10 for Practical Advice
10/10 Helpfulness
10/10 for Accounting for my lack of $
;)

EDIT: In all seriousness I could do that, but mechanical drawings are far easier and more precise.
I will look for something though, if it becomes my only option.
 

Valantar

King of Cable Management
Jan 20, 2018
646
477
AFAIK EATX is poorly defined and rarely followed as a standard, with most "EATX" motherboards just being slightly larger than ATX in various ways, with others being called EATX despite being server form factors or similar. In short: this is going to be a challenge, and unless you're going very large, you're unlikely to achieve complete compatibility with boards larger than ATX. The "EATX" Asus Strix X399 in my partner's workstation uses standard ATX mounting points as it isn't actually big enough to fit anything more despite being wider and taller than ATX.
 
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Windfall

SFF Guru
Original poster
Nov 14, 2017
1,498
1,175
AFAIK EATX is poorly defined and rarely followed as a standard, with most "EATX" motherboards just being slightly larger than ATX in various ways, with others being called EATX despite being server form factors or similar. In short: this is going to be a challenge, and unless you're going very large, you're unlikely to achieve complete compatibility with boards larger than ATX. The "EATX" Asus Strix X399 in my partner's workstation uses standard ATX mounting points as it isn't actually big enough to fit anything more despite being wider and taller than ATX.
So just have standard ATX mounting and leave some space, I guess.

Thanks!
 
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AMv8-1day

Cable-Tie Ninja
Feb 13, 2017
145
115
So just have standard ATX mounting and leave some space, I guess.

Thanks!
Basically.
EATX is kind of a bastardization of the ATX formfactor with allowances for boards matching up to the SSI-EEB length and width, but not mounting points.
The best way to account for it is to base your measurements off of the standard ATX mounts with extra room past the right most standoffs for whatever extra width the board you have in mind is. For example, I have an SSI-CEB (12"x10") motherboard and an SSI-EEB (12"x14") board. EATX isn't a consistent length, but a range anywhere between standard ATX all the way out to SSI-EEB. But whatever board you're looking at should have its exact measurements on the manufacturer page. Or you could play it safe and just make enough room for a full SSI-EEB.
A real good place to start would be basing your measurements off of the Cerberus X, although a heads-up from someone that learned the hard way, despite their stated measurements, it was about 4mm too shallow to fit the full horizontal length.
 

Windfall

SFF Guru
Original poster
Nov 14, 2017
1,498
1,175
Basically.
EATX is kind of a bastardization of the ATX formfactor with allowances for boards matching up to the SSI-EEB length and width, but not mounting points.
The best way to account for it is to base your measurements off of the standard ATX mounts with extra room past the right most standoffs for whatever extra width the board you have in mind is. For example, I have an SSI-CEB (12"x10") motherboard and an SSI-EEB (12"x14") board. EATX isn't a consistent length, but a range anywhere between standard ATX all the way out to SSI-EEB. But whatever board you're looking at should have its exact measurements on the manufacturer page. Or you could play it safe and just make enough room for a full SSI-EEB.
A real good place to start would be basing your measurements off of the Cerberus X, although a heads-up from someone that learned the hard way, despite their stated measurements, it was about 4mm too shallow to fit the full horizontal length.
Thanks, that helps quite a bit!