4 ms·

> An unnecessary additional failure point seems counterproductive One of the leading reasons for using USB attached storage on the Pi is to avoid SD card corru

> An unnecessary additional failure point seems counterproductive One of the leading reasons for using USB attached storage on the Pi is to avoid SD card corruption issues.

mmastrac 6y ago
FWIW I have not had any SD corruption issues after 1) using name-branded cards and 2) ensuring that I feed each Pi w/5.2V. In the end I bought a commercial 5V power supply, tweaked it up 5% and wired directly to the 5V pins on the Pi.
- magicalhippo 6y ago
  I'm running several Pi's from SD card, some for years, and the only issue I had was with one that randomly crashed. Measured the resistance of the "USB charging cable" I had used for it and found it was 1 Ohm! So when the Pi peaked at 1A current draw, the cable dropped 1V. Swapped it out for something proper (<0.1 Ohm), and haven't had issues since.
  - mmastrac 6y ago
    Same here. I even went as far as finding barrel-jack to USB connectors so I could wire thicker-gauge cables to the Pi. In the end I gave up on trying to find low-ohm cables and just wired directly to the power supply. It's surprising how many cables just plain suck.
adriancr 6y ago
You can get the same corruption on ssds if power draw is more then pi allows or if power goes down. With an SSD you are increasing power consumption on USB which is limited to around 1.2A or however much power supply allows. Note: I havent had any corruptions past year on pi3... all I changed was power supply, sd card and using aarch64
- wtallis 6y ago
  Presumably using an enterprise-grade NVMe SSD with power loss protection capacitors would avoid such trouble. Some of those have reasonably low power consumption under load, but they're all bad at idle compared to client/consumer SSDs. But now you also have me wondering about Intel's Optane cache SSD modules, which like enterprise SSDs don't have any volatile caching, and they're also cheap enough to make some sense in an RPi context. I'm tempted to do some voltage margin testing on one to see where it browns out compared to a typical consumer SSD.

> An unnecessary additional failure point seems counterproductive One of the leading reasons for using USB attached storage on the Pi is to avoid SD card corruption issues.

mmastrac 6y ago

FWIW I have not had any SD corruption issues after 1) using name-branded cards and 2) ensuring that I feed each Pi w/5.2V. In the end I bought a commercial 5V power supply, tweaked it up 5% and wired directly to the 5V pins on the Pi.

magicalhippo 6y ago
I'm running several Pi's from SD card, some for years, and the only issue I had was with one that randomly crashed. Measured the resistance of the "USB charging cable" I had used for it and found it was 1 Ohm! So when the Pi peaked at 1A current draw, the cable dropped 1V. Swapped it out for something proper (<0.1 Ohm), and haven't had issues since.
- mmastrac 6y ago
  Same here. I even went as far as finding barrel-jack to USB connectors so I could wire thicker-gauge cables to the Pi. In the end I gave up on trying to find low-ohm cables and just wired directly to the power supply. It's surprising how many cables just plain suck.

adriancr 6y ago

You can get the same corruption on ssds if power draw is more then pi allows or if power goes down. With an SSD you are increasing power consumption on USB which is limited to around 1.2A or however much power supply allows. Note: I havent had any corruptions past year on pi3... all I changed was power supply, sd card and using aarch64

wtallis 6y ago
Presumably using an enterprise-grade NVMe SSD with power loss protection capacitors would avoid such trouble. Some of those have reasonably low power consumption under load, but they're all bad at idle compared to client/consumer SSDs. But now you also have me wondering about Intel's Optane cache SSD modules, which like enterprise SSDs don't have any volatile caching, and they're also cheap enough to make some sense in an RPi context. I'm tempted to do some voltage margin testing on one to see where it browns out compared to a typical consumer SSD.