Why can't computers boot instantly? (2013) • Hacker News Board

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

#101

Post by LocalH » Sun, Jun 23, 2019, 4:25 PM UTC

dsr_ wrote: post #69

tsjq wrote: post #54

Earlier quoted context omitted.

>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 cos…

Pretty sure the "instant on" sets also caused premature aging to the CRT. They'd keep the filament partially heated all the time.

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

#102

Post by vilhelm_s » Sun, Jun 23, 2019, 4:25 PM UTC

It could probably be faster if people cared to optimize it, e.g. some experiments to boot an embedded linux system to the console prompt in less than 1 second (https://fossforce.com/2017/01/linux-zero-boot-second/), or to the Qt Camera Preview app in 3 seconds (https://www.e-consystems.com/Articles/Product-Design/Linux-B...) or to a Debian desktop in "5 seconds" (https://wiki.debian.org/BootProcessSpeedup#Tests_results_of_...).

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

#103

Post by trn » Sun, Jun 23, 2019, 4:29 PM UTC

fulafel wrote: post #98

Trivia: some compuers have a single level memory store, so there are no separate disk and ram concepts from se PoV. I think as/400 and maybe Multics are like this. But i don't know if they boot instantly from whete they left off, probably not. It would be within relatively easy reach though.

For new install and first (cold) boot for a Multics system, the system is loaded from a Multics System Tape. As part of this process, the entire MST is loaded in Multics memory; Multics is partially started up to configure all of hardcore for the current hardware configuration; Multics then transfers back to BCE without shutdown.

BCE captures this configured Multics hardcore memory image, and saves it to a file in the BCE disk partition. BCE then returns control to Multics hardcore, so it can continue system start-up.

Subsequent (fast) boots from BCE boot the preconfigured Multics memory image, loading it from disk into memory, and transferring into the image, just as was done when the image was first saved.

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

#104

Post by Veedrac » Sun, Jun 23, 2019, 4:56 PM UTC

air7 wrote: post #85

This is a good question, and the "answer" avoid it by essentially saying "it can't be zero." Why does boot time take ~10 seconds? CPUs run in GHz, meaning 10^9 operations per second. That means that booting takes around 10^10 operations. Why that order of magnitude and not any other? Obvious answer is "that's where the optimization efforts stopped", but could it be 10^9 or 10^8? Obviously booting time isn't just (or…

10⁹ ops/s is an incredible underestimate; CPUs tend to have an IPC around 4, and at least two cores, even on mobile. Which means at 3GHz, you should have closer to 10¹¹ ops/s.

The real question is not whether a computer can boot in a second, it's whether it can boot in a frame.

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

#105

Post by agumonkey » Sun, Jun 23, 2019, 5:05 PM UTC

LocalH wrote: post #101

dsr_ wrote: post #69

Earlier quoted context omitted.

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 cos…

Pretty sure the "instant on" sets also caused premature aging to the CRT. They'd keep the filament partially heated all the time.

and premature aging of your savings

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

#106

Post by c22 » Sun, Jun 23, 2019, 5:53 PM UTC

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…

I used to achieve 1-2 second boot times by just reconfiguring my kernel to only load drivers for hardware I actually had installed. It's more like 4-5 seconds now that ASLR is a thing, but I'm not complaining.

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

#107

Post by unnouinceput » Sun, Jun 23, 2019, 6:01 PM UTC

Sephr wrote: post #81

unnouinceput wrote: post #73

Earlier quoted context omitted.

10 to 20 seconds? What monitor do you have? All decent monitors have a maximum of 5 seconds.

Unfortunately the very best LCD monitors currently all take pretty long to start up. The Asus PG27UQ (regarded as the current-best consumer 27" 4K LCD) takes almost 20 seconds to start up, presumably to initialize a bunch of state for its FPGA.

LCD? What year is this, 2005? I have LED for over a decade now, and all my friends as well.

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

#108

Post by unnouinceput » Sun, Jun 23, 2019, 6:06 PM UTC

avian wrote: post #80

unnouinceput wrote: post #70

Earlier quoted context omitted.

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, h…

> 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. Maybe the 486 was the low end of what you could buy at the time, but not everyone bought a new computer. My parents upgraded their 386 from Windows 3.1 to 95. It was slow, but usable.

In 3rd year at Uni, in good old '96 I had a P5 with W95 in my dorm room. Granted, not mine, but the friend and colleague who had it was not some rich parents kid, just middle class. We played HOMM2 on it all day long, much to his gf dismay.

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

#109

Post by unnouinceput » Sun, Jun 23, 2019, 6:09 PM UTC

karmakaze wrote: post #100

unnouinceput wrote: post #70

Earlier quoted context omitted.

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, h…

There was a long time where the 486 was the sweet spot before Pentiums were commonplace. I didn't so much run Win3x/9x but did have both OS/2 and WinNT i486 (desktop and laptop) machines with up to 66 MHz 40 MB ram before moving off them.

486 DX4 at 100MHz was something like 250 USD in 1995. I remember this perfectly because my sister in law saw this in a ad and wanted to buy it for her business and need it my help for negotiating the price down to 200 USD, since that was all the budget she had for such a purchase.

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

#110

Post by Tagbert » Sun, Jun 23, 2019, 6:51 PM UTC

unnouinceput wrote: post #107

Sephr wrote: post #81

Earlier quoted context omitted.

Unfortunately the very best LCD monitors currently all take pretty long to start up. The Asus PG27UQ (regarded as the current-best consumer 27" 4K LCD) takes almost 20 seconds to start up, presumably to initialize a bunch of state for its FPGA.

LCD? What year is this, 2005? I have LED for over a decade now, and all my friends as well.

No, you don’t. Unless you are using an OLED screen, you have an LED-backlit LCD screen. Vendors call them LED monitors because it sounds more high tech than old LCD monitors.