This is giving a voice to an open question from a number of other threads that wandered off topic.
There is a class of application such as trailcams, security cams where a really, really fast boot is essential. A typical Raspbian from a typical SD Card will take 20-odd seconds.
How fast? - Ideally in the single seconds. But how low can it go?
Here is a video of about a 3 second boot, which is mighty impressive but others have had difficulty reproducing it.
Factors I know that affect boot speed are:
- SD Card speed (this is a bit of a black art)
- Combination of boot from USB drive and SD Card
- Optimise Drivers loaded etc
How low can we go???