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Why can't computers boot instantly? (2013)

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Re: Why can't computers boot instantly? (2013)

#61

Post by amiga-workbench »

tempguy9999 wrote: post #58
galfarragem wrote: post #13

Earlier quoted context omitted.

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..

I'll beat that: I was watching a modern flat-screen fancy tv. It blacked out and rebooted while I was watching. Screw startup if they can't even stay up. OMG TVs can now crash...

Not to defend that, but it reminds me of a project for the raspberry pi that would let it output teletext signals over its composite port. The original version was a bit buggy and would crash the onboard computer in CRT TV's.

Re: Why can't computers boot instantly? (2013)

#62

Post by gruez »

adsche wrote: post #33
enneff wrote: post #25

Earlier quoted context omitted.

They can. But the more software you need to initialise the slower it is. And modern machines run a lot of software.

But then the questions are, why does it need to initialize? Why doesn't it start in an initialized state, what factors make it impossible to determine that initialized state beforehand and storing it? How close can we get?

>Why doesn't it start in an initialized state

That's sort of how Windows quick startup works. It saves the kernel state after startup, and on next startup, it restores it (kind of like hibernating the system). Iirc emacs does something similar with its lisp runtime as well.

Re: Why can't computers boot instantly? (2013)

#63

Post by planteen »

ahartmetz wrote: post #23
verisimilitudes wrote: post #3

Windows 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…

Came here to say this. I've worked on embedded Linux projects with a boot time requirement of 2 seconds and easily made it.

I guess part of the difference is that you explicitly enumerate all hardware and drivers in a device tree on embedded rather than figuring it out on the fly like on a desktop/server machine.

Re: Why can't computers boot instantly? (2013)

#64

Post by ebg13 »

gruez wrote: post #60
mojuba wrote: post #8

A bigger question for me is, why can't monitors boot instantly? So annoying that a monitor that went to sleep can sometimes take 10-20 seconds longer to wake up than the computer it is attached to.

If it's really 10-20s, I'm guessing it's because it's because it's cycling through the various input sources looking for a signal.

But it could just look at all of the input sources at the same time. And anyway, these are solid state electronics, not hamsters and flywheels. Taking seconds to send "give me electrons" and for the other side to say "here are some electrons" is bonkers.

Re: Why can't computers boot instantly? (2013)

#65

Post by mojuba »

gruez wrote: post #60
mojuba wrote: post #8

A bigger question for me is, why can't monitors boot instantly? So annoying that a monitor that went to sleep can sometimes take 10-20 seconds longer to wake up than the computer it is attached to.

If it's really 10-20s, I'm guessing it's because it's because it's cycling through the various input sources looking for a signal.

Might be that, also the computer itself might be another reason. But who cares? Why doesn't the monitor just re-establish the last known good connection quickly?

Re: Why can't computers boot instantly? (2013)

#66

Post by adsche »

magicalhippo wrote: post #43
adsche wrote: post #33

Earlier quoted context omitted.

But then the questions are, why does it need to initialize? Why doesn't it start in an initialized state, what factors make it impossible to determine that initialized state beforehand and storing it? How close can we get?

As an example, consider the PCIe bus controller. Say it had some non-volatile memory so that when it powers on, it just reads the bus configuration from the NVM instead of enumerating and initializing the devices on the bus. Lots of time saved. Well that wouldn't really work without the PCIe devices also storing the configuration in NVM. If I plug a x16 device into a x4-only slot (as is typical for the third PCIe x16…

Sure, that all makes sense, but why could it not do the initialization once (when something changes like you describe), save it, and reuse it next time?

EDIT: Ah, sorry, you're saying the enumeration/scanning for changes is what takes most of the time?

Re: Why can't computers boot instantly? (2013)

#67

Post by gonzo41 »

tempguy9999 wrote: post #58
galfarragem wrote: post #13

Earlier quoted context omitted.

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..

I'll beat that: I was watching a modern flat-screen fancy tv. It blacked out and rebooted while I was watching. Screw startup if they can't even stay up. OMG TVs can now crash...

This happened to me when i was playing xbox recently. I'm not sure if it was the game (Division 2) or the TV but it really surprised me.

Re: Why can't computers boot instantly? (2013)

#68

Post by adsche »

gruez wrote: post #62
adsche wrote: post #33

Earlier quoted context omitted.

But then the questions are, why does it need to initialize? Why doesn't it start in an initialized state, what factors make it impossible to determine that initialized state beforehand and storing it? How close can we get?

>Why doesn't it start in an initialized state That's sort of how Windows quick startup works. It saves the kernel state after startup, and on next startup, it restores it (kind of like hibernating the system). Iirc emacs does something similar with its lisp runtime as well.

Yes, I was thinking of Emacs, too. I'm basically curious why the BIOS etc. couldn't run once, store the result of initialization and then resuse that on every boot until the configuration changes.

Re: Why can't computers boot instantly? (2013)

#69

Post by dsr_ »

tsjq wrote: post #54
agumonkey wrote: post #22

Earlier quoted context omitted.

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.

>The screen would need a few seconds to finally warm up and be fully on. is that why we hear the audio before video is ready ?

Yes. The radio receiver, sound decoder, amplifier and speaker all work on very little charge and can bring you the sound in a fraction of a second after being turned on; the CRT needs to power up magnets and a particle accelerator

Late in the history of CRTs, some units kept the electron gun warmed up whenever the unit was plugged in -- so it was never all the way off. That enabled an "instant on" feature, at the cost of more power usage.

Re: Why can't computers boot instantly? (2013)

#70

Post by unnouinceput »

argimenes wrote: post #16

When I was in high school their Amiga would cold boot into a GUI within 3 seconds. It was the same for the Acorn Archimedes in the UK. These computers had the entire GUI OS burnt into the ROM. After that I remember the shock or getting a 386 and waiting minutes for Windows 95 to load. It was like the future had died and was buried by a conspiracy of silence in the industry.

386 and W95? Not a good combination. By the time W95 was out on the market P5 was the latest and greatest and a 486 was the low budget one. You might want to reconsider those memories. As for loading times it all boiled down on how many check-up you wanted or not in your BIOS. As a rule I've always did memory check by BIOS only one time when buying/putting together a new PC and after that I've check it off in BIOS, halving the time it need it to boot. It was perfectly easy to have a 3 seconds BIOS time, sometime was even a nuisance to make it that short because you'd had to be fast to press Del (or whatever the BIOS key was) if you wanted to go to BIOS instead.
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