it must be E-ATX but it seems to not be identified/confirmed anywhere.
Not much is known about the asus KGPX-D24 it seems to have been sold in the RS500A-S6/PS4 1U server
it can now be found as a stand alone board on 2nd hand marketplaces
here is the spares documentation i could find on it and an attached images of the board in question
https://15h.org/images/7/74/RS500A-S6_PS4.pdf
Not much is known about the asus KGPX-D24 it seems to have been sold in the RS500A-S6/PS4 1U server
it can now be found as a stand alone board on 2nd hand marketplaces
here is the spares documentation i could find on it and an attached images of the board in question
https://15h.org/images/7/74/RS500A-S6_PS4.pdf
![KGPX-D24.jpg](/proxy.php?image=https%3A%2F%2F15h.org%2Fimages%2Ff%2Ff6%2FKGPX-D24.jpg&hash=9b11c277c8e66d37266ea38b3d8f3b5b)