Pi 3B+ GPIO vs USB performance difference?
Is the serial connection to the einsy the same speed regardless if the pi is connected via GPIO or USB?
I recently hooked up a pi 3B+ via the GPIO pins and while printing a file from octoprint with a lot of gyroid infill, the printer was stuttering like it wasn't getting the data fast enough. It was the same stutter effect that happens if you use a pi zero and try to transfer a lot of data via wifi while it's printing. I was surprised to see this stutter with the pi 3B+, since it is so much more powerful than the zero. Printing the same gcode from the SD card works flawlessly.
I want to use the GPIO pins because I like how neat it is having all the wiring inside the case (I have a pi + einsy case). But if there is a performance hit I guess I'll have to switch back over to USB.
I really should print the same gcode from pi over GPIO, pi over USB, and SD card, so I can make a direct comparison. But, until I have time to do that, has anyone got any idea what might be going on?