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Comment by petters | Hacker News Reader

A computer and OS that boots in 100ms. Every user action gives a response in 10ms.

Well, the Atari ST booted in about one second, from black screen to moving a mouse around. A lot of that time was waiting for a floppy disk boot sector read to time out (so if you had a formatted floppy in the drive it'd spin up, quickly read a dud boot sector, and continue the boot process of the ROM-based OS rather than timing out).

I suppose if you were gonzo about it you could format the first track with sectors all numbered zero, and eliminate rotational latency. You'd save 80 ms (on average) that way.

Didn't seem worthwhile at the time :-)

We had approximately that in the 1980s. And straight to a programmable shell, too.

And then we had to wait 10 minutes for a program to load over cassette tape with a significant failure rate.

As an example of just how far we are from this, generally the bootloader hasn't even passed off to the OS within the first 100ms.

I think it's really sad, because a system would likely have to be redesigned from scratch to make this happen. So it seems unlikely to happen.

But I'm not an OS expert, maybe it is possible.

You would have to rewrite the bios and not check any of your memory.

Boot time is kind of ireelevant when everything spends its time asleep. But I strongly agree that we should try to reduce frame latency for "productivity" apps; you probably don't need 10ms as most people are still on 60Hz, but we ought to be able to manage two or three frames.

At least get typeahead working properly again. Various places have borken this, especially Facebook, but back on vt3270 systems experienced operators could just hammer a bunch of data into forms as fast as they could type. Can't usually do that with web apps.

I've used a Tempest arcade machine with near-zero latency, and it was a very weird and pleasant experience.

This is definitely not near the top of my list when I think of things that get in my way on a day-to-day basis, but I'm genuinely curious about how/why it is for you. I can't remember the last time I waited for my computer to start from a cold boot (updates apply in the middle of the night and the reboot happens then). It wakes up from sleep quick enough for me, and pretty much anything I click on or type responds fast enough to appear instant.

This probably isn't quite what the commenter had in mind, but boot time matters a lot for embedded devices. It's quite possible the "Linux box" you cold boot the most is the center console of your car.

That's a really great point: I'd love the infotainment system in my car to boot faster. But that is also not "the single top-priority software engineering problem" for me, either.

I think you make a great point. I agree that waiting for my computer to boot is a non-issue today. (Other latency certainly isn't)

But my Chromecast takes a very long time to start, modern TVs, Blurays, mobile apps etc.

Modern lightbulbs don't even turn on in 100ms. I have a hard time believing sub second computer booting is really at the top of anyone's priorities.

I think it is important for embedded, but sure, not for mobile and desktop. App start time being instant is much more important.

TVs and monitors don't even turn on in 100ms

Would you mind expounding on why this is important, and/or why you chose those specific timings?

not op but everything feels sluggish. Waiting for all the latency everywhere - over years/decades - feels really draining. i.e slow websites, slow desktop apps, slow languages, slow OS updates, slow IDEs, slow DB syncs, slow email clients.

Exactly, I wait almost a minute for my Chromecast to start every day.

My newest laptop is closer to that than any computer I’ve ever had since 1984. Mostly because of SSDs I guess, but Windows boots in a few seconds. Usually takes longer to shutdown than to boot.

10ms response is a bit on the fast side. Aside from pros doing sports or music, we (humans) don’t register most kinds responses that fast. Plus a 60hz display is 16ms anyway. These days browsers, editors, and OSes really do usually try to meet this goal for the most common workflows, though there are plenty of demonstrable exceptions. It’s a good goal, I agree with it, but maybe 100ms would be a more reasonable worst-case response time?

100ms is too slow for e.g. a pen on a touch screen. The ink will lag behind the pen.

But for worst case in general, not bad.

Yes absolutely! Drawing needs 60Hz or 120hz or better. I assumed perhaps incorrectly you were talking about one-time responses like apps opening and menu clicks and things like that. My statement above is not good for time-based motion, apps like games and drawing, those are better with 33ms response times or better, for sure, and 100ms is too slow.

Isn't that basically what a phone or tablet does?

This problem is best solved with an effective, reliable sleep/wake mechanism, not a fast boot mechanism.

On that note, the Slackware guy said that the startup speed advantage of systemd wasn't really worth it for his distro, on the reasoning that most people only rarely completely reboot their computer anyway, especially how we have hibernate and suspend today.

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