I remember there was a topic with similar symptoms, although network I/O related. Topic ended in no use of Pi5 anymore.Today I started a move on my notebook and it estimated 2 hours. I decided to move the move to my new Pi 5 8GB with the official power supply and the latest OS downloaded a couple of days ago. It should be faster than the Pi 4 with double the USB bandwidth. Instead the Pi OS file manager estimated 12 hours and the CPU temp went through the roof.
My impression is that the lower layers of SW (e.g. PCI-E <> RP1 <> USB3/RJ45 gets into a error state and/or and avalanche or recovery actions or so. With result the only very little transactions are successful or just a very low percentage of a transaction/data block. A device-to-device copy should all be done by handled by DMA, it is not that we look at a 40 year old IBM PC with the x86 CPU doing PIO instructions to shuffle data. Instead, at some point in time people could install DMA driver for their HDD I/O chip-set, then higher throughput and very little CPU overhead.
The RPI1 chip is like the "HDD I/O chip-set" in my simple modelling, so something around there is likely going fatal more or less. I do not know if the connector between the 2 HDMI can be used for outputting debug messages of what runs on the RPT1, but I would guess it can.
Maybe you can state how many bytes are involved. I would use rsync, it also can output transferspeed (rsync -avxP ...) . So what speed shall be expected?
Statistics: Posted by redvli — Mon Dec 30, 2024 2:57 pm