Using the same case as the Quadra 800, the 840av incorporated the same AV circuitry as the Centris 660av. Running a 40MHz CPU, this was Apple's fastest 68040-based computer ever. The 840av runs a faster version of the AT&T DSP chip, one clocked at 66MHz v. 55MHz in the 660av. This and the 660av were the only Quadras to use the GeoPort high speed serial port.