A lot of these answers are why computers don’t boot instantly but none really talk about why they can’t. The accepted answer talks about it on a physical/mechanical level but eschews practicality: what can’t computers boot arbitrarily quickly?
Why can't computers boot instantly? (2013)
21–30 of 167 posts
Re: Why can't computers boot instantly? (2013)
#22Windows is a bloated mess, so it's obvious there. As for anything POSIX, it's because UNIX is shitware; it took a long time to boot decades ago and it takes a long time to boot now, because more garbage has been piled on top. It's possible for a good operating system to boot in less than a second, however. People have simply been conditioned to accept this unacceptable state of affairs, no different than a TV that ta…
I still remember the day I got a new TV (despite old CRT working) for my parents and see their faces the first time time we turned it on. Now they are used but at the beggining the boot time was difficult to grasp: it used to be negligible with the obsolete tech..
The old world was mostly stateless. Power = function.
That said, even CRT had 'boot' time. The screen would need a few seconds to finally warm up and be fully on. But it was still a mind free system, you knew that your were done with the boot process and could enjoy 90% of functionality.
Re: Why can't computers boot instantly? (2013)
#23Windows is a bloated mess, so it's obvious there. As for anything POSIX, it's because UNIX is shitware; it took a long time to boot decades ago and it takes a long time to boot now, because more garbage has been piled on top. It's possible for a good operating system to boot in less than a second, however. People have simply been conditioned to accept this unacceptable state of affairs, no different than a TV that ta…
There are embedded Linux demos that boot into a GUI application in about a second. Linux systems don't boot slowly because "POSIX" isn't capable, it is a matter of boot time vs. flexibility and developer convenience / development time. There are also Windows CE systems that boot that fast. Linux demo: https://www.toradex.com/de/videos/fast-boot-demo-with-linux-...
I have a few moderate boot time improvement projects on embedded Linux under my belt. The typical low hanging fruit are hardcoded wait times in boot loader and drivers, unnecessary drivers, unnecessary features (did you know that PPP - yes, the modem thing - support takes a while to initialize?), slow to mount filesystems, bad choice of storing / compressing the kernel, and delays in the init system (run the application as soon as possible instead). More hardcore techniques are various methods to reduce dynamic linker overhead and reordering blocks on storage in the order they will be read at startup.
Re: Why can't computers boot instantly? (2013)
#24Has someone explored the area of writing software that spits out resume from disk images?
You mean hibernation? That exists for a long time now, but is technically not booting.
Alternatively, booting is just an inefficient "resume from disk", using a generic initial state instead of one adapted to the device.
Re: Why can't computers boot instantly? (2013)
#25A lot of these answers are why computers don’t boot instantly but none really talk about why they can’t . The accepted answer talks about it on a physical/mechanical level but eschews practicality: what can’t computers boot arbitrarily quickly?
They can. But the more software you need to initialise the slower it is. And modern machines run a lot of software.
Re: Why can't computers boot instantly? (2013)
#26My POST sequence takes longer than the boot process so no matter how blazing fast my drives are it still takes a long time to get to the boot loader.
Re: Why can't computers boot instantly? (2013)
#27I'm pretty happy with boot times, the longest wait is the boot loader and inputting the password. (Linux with full disk encryption).
Re: Why can't computers boot instantly? (2013)
#28Because of state.
Re: Why can't computers boot instantly? (2013)
#29I have a question too: why does radios take so long to start up and acquire a signal? Same for other I/O devices similar to radios，on the embedded side you have keep on polling until finally it acquires the signal.
Re: Why can't computers boot instantly? (2013)
#30That is not a good answer. It's perfectly possible for computers to boot in a fraction of a second.
The argument that computers need to go from a useless state S0 to a useful state S1 and that takes a long time is just bullshit. The question is, how close can you bring S0 to S1. This is a question of optimization. What happens is that S1 is different for different computer configurations, and processing needs to happen. Then the question becomes, how much effort do software companies spend optimizing that processing? The answer is "as much as they feel that they need to."
Computer boot times have been constant over many years because performance gains enable companies to add more features. As long as the boot time stays within tolerable bounds for the typical user, there is no need to optimize further. But there are tons of other computer systems in the world (particularly embedded) that must boot instantly, and they do so.