C-Media (CMI)

C-Media used to be very popular, especially on low-end motherboards, and they manufactured both codecs and complete audio controllers. Audio controllers usually need an external codec to do the analog-to-digital and digital-to-analog conversions, but C-Media’s low-end audio controllers have a codec embedded inside the chip, which is why we will include them in the table below. Because of that, we included a column called “type” to let you know if the chip is just a codec requiring an external controller (e.g., connected to the south bridge chip) or if it is a complete controller with an embedded codec (usually connected to the PCI bus). Chips from C-Media use names starting with the letters “CMI,” as you can see on the example shown in Figure 3.

C-Media CMI9739A codecFigure 3: C-Media CMI9739A codec

Model Type Channels Input Resolution Output Resolution Input  Max. Sampling Rate Output Max. Sampling Rate Input SNR Output SNR
CMI8738-LX, CMI8738MX Controller 5.1 16-bit 16-bit 48 kHz 48 kHz 80 dB 80 dB
CMI8738-SX Controller 4 16-bit 16-bit 48 kHz 48 kHz 80 dB 80 dB
CMI8768 Controller 7.1 16-bit 24-bit 48 kHz 96 kHz 86 dB 101 dB
CMI9738 Codec 4 20-bit 20-bit 48 kHz 48 kHz 72 dB 82 dB
CMI9739 Codec 5.1 20-bit 20-bit 48 kHz 48 kHz NA NA
CMI9761 Codec 5.1 20-bit 24-bit 48 kHz 96 kHz 90 dB 92 dB

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