Placement of motherboard holes for systems bigger than ATX but not standard sizes
Placement of motherboard holes for systems bigger than ATX but not standard sizes
Yes, the main difference is typically that the board itself is wider than a standard ATX board. The issue with eATX and other larger motherboard sizes is that until you get up to SSI-EEB, CEB, and MEB, there's basically no standardization whatsoever in terms of dimensions, so some cases will fit some eATX boards but not others. There is very little consistency for motherboards between ATX and SSI-EEB. https://www.gamersnexus.net/guides/3566-...tx-eeb-ceb
These boards appear under EEB and HPTX categories. They don't fall under the E-ATX classification, though manufacturers use E-ATX to signal ATX-style screw holes with a broader board profile.
In those edge cases, it seems likely that 3 or 4 holes could align, otherwise the arrangement would be entirely different.
Typically EATX boards are just a bit wider than ATX, and sometimes they’re slightly taller too—perhaps an extra slot of vertical room. Most motherboards retain the screw holes in the same spots as ATX, with additional holes on the right edge. You can use nylon spacers or similar techniques to prevent flexing and contact with the case metal. Just make sure the back plate doesn’t have any bumps or odd shapes that could interfere with the board.
Great, even with imperfect mounting, the larger nonstandard boards still appear secure in my testbench.