not that dell is any kind of help and leaves you in the wind but at ebay [???] they show there seems to be 3 boards used ??
Compatible Dell Part Numbers: XPDFK, K095G, 9KPNV. This is a USED Genuine Dell Precision Workstation T3500 Motherboard.
sad when e-bay gives more info the dell on there own products?
now here they say ''Product Dimensions 18 x 16 x 13 inches
http://www.amazon.com/Dell-Precision-Workstation-Motherboard-XPDFK/dp/B00UR3U0LY
the look here at page 10 ?? is larger then atx ?
http://www.formfactors.org/developer%5Cspecs%5Catx2_2.PDF
thing is with dell is it a proprietary board ?? I was looking at that hump on that one side of the board that don't seem to be standard atx of any kind ??
kinda like how dell uses btx boards as well ????