The AC-97 audio codec is a piece of software that interacts with audio hardware that is embedded onto a motherboard. In some cases, this hardware is also found on a dedicated PCI or PCI-Express expansion card. These cards contain the necessary digital-to-analog conversion hardware and allow physical connection of audio input and output devices. These devices include microphones, headsets, recording devices and speaker systems.

Audio expansion cards in this class typically do not contain a microprocessor for audio processing. In order to fill this need, the AC-97 software is installed onto a computer and runs in the background. There, it uses cycles on the system's CPU to perform audio operations. Although this keeps hardware costs down, it can place an extra burden on the CPU. This is especially true when 5.1, 7.1 or higher audio standards are used. Effects such as Dolby Digital, EAX and SRS WOW can increase CPU utilization substantially. Adding a sound card with an onboard microprocessor is a common means to speed up gaming computers whose processors are overburdened by these operations.

Audio chipsets that rely on the AC-97 audio codec are typically found on motherboards. They are frequently a small chip that is wired directly to the "south bridge" chipset component. In other cases, the relevant hardware is embedded into a larger integrated circuit. This hardware will often identify itself to Windows as a generic audio device. In some cases, it will identify itself as an AC-97 device. This hardware will not function properly without the AC-97 codec software.

This software is typically found on a motherboard manufacturer's website or a CD-ROM included with the motherboard or pre-built computer. In the event that this cannot be located, a generic AC-97 installation package can be used. Note, however, that specialized releases including the AC-97 codec software also include specialized control panels and utilities that unlock certain features of specialized hardware. When possible, use the audio hardware manufacturer's recommended software.