An Advanced Technology eXtended (ATX) case is a computer case made to ATX industry standards. The ATX standard is a format for manufacturers of computer hardware that ensures interoperability. The ATX case will accommodate an ATX power supply and ATX motherboard.
The ATX case grew out of shortcomings of prior standards, namely the AT and Baby AT standards. As technology has improved, many significant changes have been made in hardware that required a newer style case. This case is the natural evolution in computer case design.
For example, component-laden computers require more power today than they did in the early 1990s, and more cooling capability. Power supplies and power schemes have become more powerful and efficient. An ATX case often comes with a power supply, or the consumer can purchase an ATX power supply separately, knowing it will work in any ATX-style case.
The back of the ATX case has also changed to accommodate ATX motherboards with built-in ports that drop into place to form a portion of the back wall. This replaces the old style Baby AT cases that were designed for empty IDE slots, with the only built-in port being the keyboard port. The holes in the ATX motherboard also align with posts on the case.
The number of internal and external bays varies on ATX cases, so it is important to choose one that will accommodate your desired setup. A Redundant Array of Independent Disks (RAID) configuration using several hard drives will require more bays than might be necessary for a system that will only be housing one or two hard drives.
If two DVD drives are desired, be sure the case has the required number of 5.25-inch (13 cm) bays. The front of the case can also feature Universal Serial Bus (USB), Firewire, and audio ports. This is very convenient for today’s portable devices, such as digital cameras, audio players and memory sticks.
An ATX case comes with fans in most cases. The size and number of fans varies between models. Fans are necessary to move heat away from the motherboard and processor, and out through ventilation slats. The more ventilation, the better.
Modderslike to spruce up their ATX cases with LED lights. Many feature clear side windows so that the inside of the case can be lit up when powered on. This allows the enthusiast to see the expensive components he or she has purchased.