Extended micro atx question

[randomdean100]

So, this isn't really an issue but more of a general motherboard sizing question. I was under the pressumption that micro atx and atx form factors were a standard, uniform size. This has been challenged by the recent install of a seemingly overly wide Matx MSI b660-pro a motherboard in a build for my brother recently with a 12400. Is this sizing new to alder lake, just this specific board, or has matx always been more like e-atx with an un-uniform sizing. The board seemingly went all the way out from io panel widthwise to the eatx sizing on a corsair 4000d. This is just a general question relating to potential future build knowledge for compatibility of parts.

 

[Nobu]

Which specific model are you talking about? There are several "Pro B660" motherboards, and none have just "B660" in their name.

And yes, uATX motherboards have always varied a bit in size, although most adhere to the minimum size specified in the standard. Some are a bit longer or shorter depending on the number of pcie slots and other peripheral ports on the bottom of the board, and some are a bit wider to allow more memory slots or vrm components to fit.

 

[randomdean100]

That would be this particular board. I was unaware there was a uatx standard I just saw it as a chonky matx. Funny though it's branded as matx. My apologies I should have capitalized that A. I meant the pro-b660m A version.

https://www.msi.com/Motherboard/PRO-B660M-A-DDR4

 

[Nobu]

Specs page says it's 9.6"x9.6", which is standard uATX (micro-ATX) dimensions, and it does appear to be just wide enough for the standard holes. Are the boards you used before smaller, maybe?

 

[randomdean100]

Specs page says it's 9.6"x9.6", which is standard uATX (micro-ATX) dimensions, and it does appear to be just wide enough for the standard holes. Are the boards you used before smaller, maybe?

Much smaller. G1 gaming gigabyte g38.9" x 6.85" and some 775 matx boards.

 

[Nobu]

That gigabyte board might have been built to mini-dtx dimensions and marketed as matx since that's (technically) the smallest atx spec case it would fit in. mDTX is just slightly smaller than that board in width and height, at 8" x 6.7".