4 ms·
SD cards as present on Raspberry Pi, even the Pi 4, don't go beyond ~60MB/s. Older Pis get around ~20MB/s. It's the worst bottleneck of the system. Where do you
by jng 6y ago
SD cards as present on Raspberry Pi, even the Pi 4, don't go beyond ~60MB/s. Older Pis get around ~20MB/s. It's the worst bottleneck of the system. Where do you get that 1 GB/s figure from?
- vardump 6y agoOh yes, another one of my pet peeves with Raspberry Pi: ancient slow SD implementation. https://en.m.wikipedia.org/wiki/SD_card https://en.m.wikipedia.org/wiki/SD_card SD Express can do up to 985 MB/s. SD UHS-II @300MB/s would be plenty for most SBCs.
- gjsman-1000 6y agoDo be aware that the Pi 4 increased the SD Card Reader speed, almost by double, I hear.
- vardump 6y agoSure, but I still can't even use my 5-6 years old Samsung Pro microsd 64 GB card at full speed, 90-100 MB/s read & write!
- dfox 6y agoBear in mind that SD Express is SD only in name and otherwise it is just an NVMe in SD form-factor. And how much UHS-II is still an SD is somewhat questionable.
- vardump 6y agoTrue. But on the other hand similar to how for example USB standard has developed from USB 1.0 to USB 4. While it would technically be correct, no one says new USB standard X is USB in name only. Perhaps every data transfer interface standard eventually adopts a PCI-e lane. :-)
- gjsman-1000 6y agoRemember that on a Pi, you can boot from a USB flash drive or Network...
- snvzz 6y agoThis is more like, you should. Because the SD interface sucks.