Troubleshooting • SSD's wont write faster than 45 MB/s... why??

Hi there.

I wrote some posts about my issue, that I thought was ethernet issues, but now I got aware of, that it must be something else.
I did some more testing with my Pi's. So far I only tested read-speed on the SSD's with Hdparm. Now I did write tests with dd, and with any combination of my 256GB Adata SSD, 1TB Samsung SSD, 4TB TeamGroup SSD and the Pineberry SSD Hat, Pimoroni SSD hat and USB-C enclosure, I get 42-45MB/s for all of them. How does that makes sense??? Of course that kinda explains why I can't obtain more than 20MB/s write speed to the Pi via my home ethernet. I also made the write tests on both of my Pi 5's. So it seems like a systematic error on... what? Any SSD of mine or both Pi 5's?? My 1TB Samsung SSD is an older one and should be expected to consume less power than any other of my new SSD's (according to the rating only 1.5A vs. 2.5 with the others).
What can possibly explain the slow write speed to the SSD's? Is there some secret setting on the Pi that I missed? A setting that limits the write speed to a SSD??

Best Ulrich

Statistics: Posted by ullenulle — Sat Mar 09, 2024 2:22 am

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