I think the slow Raspberry Pi goes into an I/O wait state and while waiting the CPU clock is reduced to save energy. It's possible the SD card on the slow Pi is slower or about to wear out. If running with USB boot, as you already noted there may be USB connectivity problems.I have two a raspberry 4b. Comparing the performance between the two units, I've noticed an EXTREME speed difference to the point where one is unusable. The symptoms I am seeing include:
USB not negotiating correctly on some devices.
10-100 byte/s write speed (while running updates).
I wrote a small script that logs vcgencmd measure_clock arm and plots it for 10 minutes and I have found that the 'bad' raspberry pi has significantly more clock speed drop outs than the 'good' system.
How can I further debug this? What might be going wrong?
If SD card, I'd replace it. If USB, I'd try reseating the cables and maybe use the other socket.
Statistics: Posted by ejolson — Tue Sep 10, 2024 3:16 am