DTX is a form factor for motherboards, a variation of the ATX form factor. It was originally developed by AMD in January 2007 and was designed for smaller computers like home theater PCs (media center computers). The physical dimensions of a DTX motherboard is 8.0 inches by 9.6 inches and the board allowed for 2 expansion slots. A somewhat smaller version was also developed, called the Mini-DTX, having dimensions of 8.0 inches by 6.7 inches.
The DTX form factor provided a lower cost of manufacturing, due to the fewer layers of printed circuit board wiring required to make the board. It was intended to be an industry standard for small form factor computers, like the Shuttle "SFF" design. DTX motherboards are backward compatible with the ATX form factor, fitting in computer cases designed for ATX motherboards. It also works with a standard power supply, requiring the same 24-pin power connector that the ATX motherboard requires.
Also see: Motherboard