The microATX form factor was developed as a natural evolution of the ATX form factor to address new market trends and PC technologies. While offering the same benefits of the ATX form factor specification, the microATX form factor improves upon the previous specification in several key areas. Current trends in the industry indicate that users require a lower-cost solution for their PC needs. Without sacrificing the benefits of ATX, this form factor addresses the cost requirement by reducing the size of the motherboard. The smaller motherboard is made possible by reducing the number of I/O slots supported on the board. The overall effect of these size changes reduces the costs associated with the entire system design. The expected effect of these reductions is to lower the total system cost to the end user.
Through careful designing of a microATX motherboard, an OEM can capitalize on the benefits of a reduction in total system costs. These cost savings come from a reduced-output power supply (see the separate document SFX Power Supply Design Guide), reduced chassis costs, and minimal redesign of existing ATX compliant chassis for backward-compatibility.
microATX benefits also include those found with the current ATX form factor: more I/O space at the rear and reduced emissions from using integrated I/O connectors.