That was exactly it. The system load flatlines to zero once the module is removed. As you mentioned, it doesn't explain why the two waveshare models would be so different, but it gives me a direction to follow up elsewhere.The touch controller on almost all these panels is polled as there is no spare GPIO for the interrupt signal. I suspect that is probably most of the extra load, although no particular reason that the 2.8" display is worse than others as almost all the Waveshare panels (and the Pi Touch Display 2) use the goodix_ts kernel module as they are Goodix touch controllers.
"sudo rmmod goodix_ts" and see if you get load numbers you are happier with.
I appreciate you taking the time to share your knowledge.
Cheers.
Statistics: Posted by dormouse — Tue Mar 03, 2026 1:06 am