Storing data from Arduino without Serial print- High Sample rate For my work, I need to acquire data at a high sample rate (&gt;100kSa/sec) using Arduino Portenta H7, which has 3 X 16-bit ADCs. Portenta H7 has STM32H747XI microcontroller. I don't want to use Serial.print command as I came to know that this command takes much time to execute, which makes achieving the targeted sample rate impossible.  What are the other possible ways to store the data from Arduino while maintaining this high sample rate? For example, saving the data and then printing them all at once at the end of testing( 3-5 second testing period). e.g. using an SD card or through saving in Arduino internal memory? Can you suggest techniques employed for high-sample rate data acquisition from Arduino?
The Portenta has a beast of an  STM32H7 Cortex M7 and a minimum of 8M bytes of external SDRAM in addition to the 1M on-chip.
You need to capture 2channels x 2 bytes x 100K/s x 5s = 2M bytes of data, so storing it on the on-board RAM and spitting it out later seems like a viable and low-risk approach.
A slow serial link might take a few minutes to transmit 2M bytes of data, but you have various other options if that is objectionable.