Hello everybody,

I have a question concerning Teensy 3.6 vs 4.0 for audio processing. Which one should I buy?

I have used the Arduino Uno for years. I really enjoy it and I have tried to do some audio.
The best I have achieved on the Uno so far is to play audio using the 16 bit timer as a clock (at 16 kHz) and an external DAC with a 12 bit resolution (16 bit resolution DACs are really expensive in the DIP format).
I have managed to play some audio either pre-loaded in the program memory (32kB, so less than 1 second) or using an SD card. But the size of the files is restricted.

Therefore I want to buy a Teensy now.

My question is which Teensy should I buy: 3.6 or 4.0? The 4.0 looks really cool, but I believe that the 3.6 is more documented?

Since I might do some "heavy" computation such as FFTs, is the Teensy 4.0 a better choice?
I have seen this graphic that seems to show the 4.0 is far better the other microcontrollers but I do not really understand what the graphic is related to.

Also I have another motivation for buying a Teensy. iI would like to get familiar with 32 bit ARM MCUs. I have learned to program the Arduino Uno both in C and assembly language and I enjoy it. I want to learn to do so on a more complex microcontroller.