All this guessing and conjecture is pointless. Someone should simply measure what takes so long with the profiling tools available and post an analysis.
Why can't computers boot instantly? (2013)
131–140 of 167 posts
Re: Why can't computers boot instantly? (2013)
#132Earlier quoted context omitted.
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.
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Re: Why can't computers boot instantly? (2013)
#133What gets me is how long servers take to reach the bootloader from power on. Your average modern Dell/HP desktop or laptop is there within a second or two, Windows 10 and systemd-based Linux distros on SSD can be at the login prompt within 5 seconds total. I haven't touched a Mac in a long time but I'd bet they're no worse.
But a typical server BIOS takes 3-5 minutes do its thing. If you're lucky you might be able to disable enough stuff to shave off a minute. Insanity.
Re: Why can't computers boot instantly? (2013)
#134Earlier 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?
The fact that reboots happen mostly when software (kernels, system) is upgraded is part of it. It's simplest and most reliable to initialize the system from clean state (I've often had an idea it would be best to reinstall Windows+software for each reboot).
There was a hard drive on the market in the past for high-security use that had write-protect and an admin mode. Maybe a PIN or something to get to admin mode. Memory getting fuzzy on it. The normal usage would be read-only with you saving your data elsewhere or to a write-able partition that had nothing to do with read-only part for OS and apps. Go into admin mode to change those. Otherwise, your system is fresh every boot.
People do it with VM's, too. I think you were aiming for something physical with no extra software. That was closest thing I could think to it.
Re: Why can't computers boot instantly? (2013)
#135Earlier quoted context omitted.
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.
Actual observed IPC tends to be 1 or less unless you are running well tuned computational workloads. And mostly software doesn't utilize multiple cores well.
Even ‘perf stat libreoffice ./somedocument.odt’ give an IPC of almost 2, and that's hardly a well-tuned computational workload.
> And mostly software doesn't utilize multiple cores well.
Most software sucks, that's the point of this whole conversation.
Re: Why can't computers boot instantly? (2013)
#136Here's a proposal..
Don't do any network stuff during boot, and don't let it depend on anything super volatile like user files.
Then store the boot memory state as an image (like a hyberfile).
Whenever a bigger change happens to the system that will affect the boot state, like installing a new driver, or an app that has any kind of background service, recreate a new boot image. But do it right away when the new app is installed, don't wait for the next boot, or shutdown (which is annoying), just do it in a virtual machine right away as part of the app/driver install. Installing impactful apps will take longer, but that can happen in the background and is not too disruptive, and doesn't happen very often anyway.
Re: Why can't computers boot instantly? (2013)
#137Earlier quoted context omitted.
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.
That said, LED backlit LCDs are better than the old CCFL screens.
Re: Why can't computers boot instantly? (2013)
#138Earlier quoted context omitted.
The two hard things in computer science are naming things, and cache invalidation. Remember; the computer could quite literally have been completely reconfigured out from under the BIOS. Testing that everything is the same from the computer's point of view is anything but straightforward. Also, most recognizable boot time isn't spent waiting on BIOS and POST; it's spent waiting for either the boot loader, disk encryp…
Usually the configuration stays the same, though - why not a way for the user to indicate when it has ? Hold down an awkward combination of three far-flung keys while booting, the BIOS wakes up and checks every device plugged into it, otherwise it just pulls it in from a cache. (And how much does the average computer's config change? How many users never change a single part of the hardware configuration of their com…
As someone who worked on boot up sequence in Windows, that won’t work. You could kill components in the system if someone forgets to press the right keys on bootup. The snapshot method you mention is essentially how it already works
Re: Why can't computers boot instantly? (2013)
#139Hibernate is my preferred option when going off the computer but Windows doesn't offer it out of the box and more. You have to tweak settings. Why is that I wonder?
My guess is the same reason modern UIs suck: too complex for the average non-technical user to handle. They probably got tons of support requests asking what the heck the difference between "sleep" and "hibernate" was, and that's a hard question to answer if the person asking has no idea what RAM is...
Re: Why can't computers boot instantly? (2013)
#140Earlier quoted context omitted.
// What happens is that S1 is different for different computer configurations, and processing needs to happen. The computer and OS config doesn't change often. And it's doesn't seem slow to test that. So caching at boot should work. And caching is a low effort optimization. So it should have been implemented early. But we don't have caching at boot, why?
The two hard things in computer science are naming things, and cache invalidation. Remember; the computer could quite literally have been completely reconfigured out from under the BIOS. Testing that everything is the same from the computer's point of view is anything but straightforward. Also, most recognizable boot time isn't spent waiting on BIOS and POST; it's spent waiting for either the boot loader, disk encryp…
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