MicroATX different from Mini ATX
Expandability
Most modern ATX motherboards have a maximum of seven PCI or PCI-Express expansion slots, while microATX boards only have a maximum of four (four being the maximum permitted by the specification). In order to conserve expansion slots and case space, many manufacturers produce microATX motherboard with a full range of integrated peripherals (especially integrated graphics), which may serve as the basis for small form factor and media center PCs. For example, the ASRock G31M-S motherboard (pictured right) features onboard Intel GMA graphics, HD Audio audio, and Realtek Ethernet (among others), thus freeing up the expansion slots that would have been used for a graphics card, sound card, and Ethernet card. In recent years, however, it is common even for ATX boards to integrate all these components, as much of this functionality is contained in the typical northbridge–southbridge pair.In the DIY PC market, microATX motherboards in general are favored by cost-conscious buyers, where cost savings for the equivalent feature sets outweigh the added expandability of extra PCI/PCI Express slots provided by the full ATX versions. Since 2006, dual-GPU configurations became possible on microATX motherboards for high-end enthusiast gaming setups, further reducing the need for full ATX motherboards.In addition, some microATX cases require the use of low-profile PCI cards and use power supplies with non-standard dimensions.Compared to Mini-ITX, microATX motherboards have a maximum of four expansion slots and four DIMM slots, as opposed to the single expansion slot and two DIMM (or SO-DIMM) slots on Mini-ITX motherboards. This means that microATX allows dual-graphics card and quad-channel memory configurations.Notes