ATX as a power supply form factor defines the dimensions, electrical current, and cables of a desktop power supply, designed specifically to be compatible with ATX and similar motherboards.SummaryATX (Advanced Technology Extended) is a and form factor and configuration specification developed by. It aimed to improve on previous such as the. Originally r. As of 2012, ATX is the most common motherboard design. Other standards for smaller boards (including,,, and ) keep the basic rear layout but reduce the size of the board and t. In 2004, Intel announced the (Balanced Technology eXtended) standard, intended as a replacement for ATX. While some manufacturers adopted the new standard, Intel discontinued any future development of BTX in 2.