I'm still unclear why you acquire stuff in an array to spit it out later in one go if you need to constantly monitor a stream
print will block when you've filled the output buffer, so that's going to be your limiting factor. You should set the Serial line at 2,000,000 bauds if the other side is a modern computer that will create less of a lag
you can use millis() to pace the acquisition
void setup() {
Serial.begin(2000000); // go as fast as your Serial line can go to not block the code if possible
}
void loop() {
static unsigned long lastChrono;
unsigned long currentChrono = millis();
if (currentChrono - lastChrono >= 10) { // ~100Hz
Serial.println(analogRead(A0));
lastChrono = currentChrono;
}
}