hdtodd wrote: ↑
Fri Mar 30, 2018 2:38 am
Is it the case that ALL USB 3.0 drives SHOULD boot on the RPI-3B, and whether or not they should, has anyone else found drives or interfaces that either won't boot (ever) or require 4-6 attempts before they boot?
It's the case that not all USB devices will boot on the RPI-3B, regardless of interface speed. The bootloader in the SoC is small and simple, due to limited space, so it's not compatible with some USB devices. Some will not boot at all. Some will boot when the system is powered on, but will not complete a restart or shutdown reliably, etc... It's all a bit of a crapshoot.
My first impression of Pi3B USB boot was pretty disappointing. I tried several different devices and none of them would work reliably. I had a bunch of other USB storage devices I wanted to try, but we were moving and most of my stuff was in boxes. Well, I recently stumbled across those boxes and tested the rest, and the only ones that didn't work, out of more than a dozen devices, were the first ones I tried.
So... things aren't as bad as I had originally thought with the Pi3B USB boot, but there definitely are incompatible devices.
Note that there is a 5 second delay before the SoC will attempt to boot a USB device, and that is enough time for some USB hard drives to spin up and get ready, but not all. For USB boot from a hard drive, it's best to power the drive independently from the Pi3B, and spin it up before you boot the computer. Also note that the Pi1B+ and Pi2B v1.1 default to only 600mA from the USB ports until the OS loads, and that may not be enough to spin up some USB hard drives (especially USB 3.0 drives). So it's even more important to power the HDD independently on those earlier models.
Solid State Drives (SSD) don't have the start up delays or power issues of mechanical spinners. I've been running one Pi3B and a new 3B+ off of SSD, and that rocks. In spite of the speed limitation of the USB 2.0 ports, it's much faster than using a micro-SD card (even a really fast one).
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?