I am rather new to microcontroller programming and electronics in general and would be very grateful for some help with a project I am working on.

I'm sorry if all if that has already been answered elsewhere, maybe I didn't search for the right terms.

I have three analog signals that I have to read with a frequency of about 10 kHz and a 12 bit resolution and I am worried about the time all of that takes.

For two signals, I should be able to use the two ADCs on the Teensy 3.6 to have two simultaneous conversions, right? But how simultaneous is that really? I always assumed that commands in the code were done sequentially. If I write two analogReads for different ADCs directly after one another, would the program wait the multiple clock cycles that the first conversion takes before initiating the second, or would the second one be started directly after the first, with their results coming in almost at the same time?

For the third signal, I would have to use another pin of an ADC that already converted one of the other two signals. Is that the fastest way to get all three signals or am I missing a better possibility I am missing? I have to do some calculations with the signals before the next ones come in and would love to spend as few clock cycles as possible on the signal reading.

Thanks to everyone in advance!