The Helix is not designed to be a fast ripper. It does not have the memory or CPU power to do that. It is a system on a chip with very limited capabilities.
The B3 is based on a Raspberry Pi B+, the same as the B2. It will support a much faster ripping capability compared to the Helix. The RPi however is also limited power means that you do not want to play or anything else while you are ripping a CD. Memory and CPU power can become clogged leading to errors. The B2 ripping was a lot more limited by the CD drive itself, not the RPi.
Ripping using an off the shelf drive is dependent more on the drive and on the quality of the CD. The CPU can easily handle the 16 bits at 44.1KHz times 2 (left and right channels). It is not really the CPU that is limiting things.
The process of ripping creates WAV files. The ripping process just formats the data stream and write it out. The conversion from WAV to FLAC however takes a much longer time.
The actual playback of the signal is trivial to the CPU. It sends the data to the DAC that provides input to the amplifier. The amplifier is a separate board and does not need the RPi to do anything more than command and control, send data and volume commands.
The operation of the AMP is at the same complexity as sending out the analog and optical ports on the B3+. When you select both options, the RPi has to send data to both devices. Data is sent to the DAC on the Brennan custom board to a the DAC that provides analog output to the on board amplifier. To send data out the analog and optical port the Brennan sends the data to a chip on a daughter board that makes this conversion. It is the same amount of work for the RPi to do both functions, internal and external. Even on the B3, if you connect a UCA222, exactly the same thing happens, data is sent using the USB to a chip/daughter board to make all of the conversions.
Ray
B3 is playing Hello Dolly by Louis Armstrong from "Louis Armstrong Sings Back Through the Years D1 of 2"