Which of these motherboard form factors has the largest maximum dimensions?

ATX (not listed above). The most massive and widespread motherboard form factor, ATX, was created by Intel in 1995. The typical size of an ATX motherboard is about 9.6 x 12 inches.

EATX: 13″ x 12″ – A full featured ATX motherboard with an extended 13″ width and 12″ height instead of the maximum ATX dimensions of 12″ x 9.6″. This form factor is also widely used in rack servers.

BTX: 12.8″ x 10.5″ – Released by Intel in 2004 as a replacement for the ATX form factor, BTX boards brought improvements, including improved thermal performance for power-hungry components such as the Pentium 4. In the . the standard BTX layout, RAM slots and expansion slots were parallel to each other. PC manufacturers including Dell used this form factor for some machines, but it never caught on and was canceled (also by Intel) in 2006.

Ultra ATX: 14.4″ × 9.6″ – Designed by Foxconn and first shown on the F1 prototype motherboard at CES 2008, this form factor is essentially a larger version of ATX that requires a Full Tower chassis.

XL-ATX: 10.3″ x 13.5″ – EVGA released the first XL-ATX board in 2009 (X58 Classified 4-way SLI), while Gigabyte and MSI released their own models in 2010. But, as in With most of these form factors, you’ll be hard-pressed to find a new one on sale today.

HPTX: 15″ x 13.6″ – A year after the release of its first XL-ATX board, EVGA released the first board in the HPTX (“Super Record 2” or SR-2 mobo) form factor, which was designed to accommodate two processors with QPI LGA 1366 socket and 12 DDR3 RAM slots.