Hello,
I recently plugged in a new Samsung SSD to a stata to usb 3.0 adapter to make it external and use it with pi0w. Until now I was using a relatively slow flash drive to store some things and I decided to upgrade a little bit. I wasn’t expecting much but at least something better than the flash drive.
I made a test using dietpi-drive_manager and the results were disappointing. The write speed was 3MiB/s, same as the flash drive. I made sure that the power supply is sufficient and also tested the ssd using usb on my PC which worked as expected.
Is there a limiting factor on pi0w that makes its usb transfer rate so slow? Is there a way to make it write a little bit faster? I don’t expect much but at least 15-20MiB/s would be good.
RPi0w only can do USB 2.0…so no matter how fast a SSD is…it can only read/write at USB 2.0 speeds So max of 480~Mb/s
It’s not that. If it could reach at least half of USB 2.0 speed it would be around 20MiB/s but not it’s at 3MiB/s for write. As I mentioned, the SSD and the usb-sata case are new and on PC it works at full speed so I thought that it must be that the pi is uncapable of handling something but I saw that people with pi4 had similar issues.
I just tested the rw speeds on the installed sdcard and the results are the following. I would expect at least something similar for the ssd.
Edit: The flash drive was indeed slow at writing and I knew this, that’s why I said that the SSD should be faster. I’m using an OTG Y cable for the connection. I can probably test it on a PC and see if the cable is the issue but I don’t think it is
│ Filesystem benchmark results:
│
│ - File path = /dietpi-benchmark_testfile
│ - Test size = 200 MiB
│ - WRITE = 16 MiB/s
│ - READ = 21 MiB/s
I tested the otg cable on my PC with a type-c to micro usb atapter and indeed it seems that the cable or the in this case the type-c to micro usb adapter should be causing the issue. I will buy a new cable to see if it makes any difference and report back
Tested on PC with a new OTG cable plugged into a micro usb to type c adapter and the results were around 40MB/s write. On pi0w it’s 1MB/s write and 20MB/s read. I even tried plugging the ssd using a powered usb hub. It doesn’t make sense. I doubt that it is a hardware issue at least for the ssd, the microusb port. I am looking and I saw also some people talking aboug the sata adapter’s chipset but could it be so bad for the raspberry?
The chipset of the enclosure is ASM225CM