Tl;dr reaction time, 300 ms is the golden rule for reaction speed, and apparently there was actually a sports medicine study that came to that #. I was surprised to see that, 300 ms comes up a lot in UX as “threshold of perceptible delay” but it was still surprising to see.

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yjftsjthsd-h 6 hours ago | parent | next [-]

I was curious, so did a quick web search, which claims that 300ms is the average reaction time and plenty of people run faster than that.

But I think the question was the other way: Why couldn't calc.exe launch in 300ms?

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refulgentis 4 hours ago | parent [-]

300 ms is way longer than they budgeted; separately, I was alive then and it's a ridiculous claim, like, it takes a general bias we all have towards seeing the past with rose-colored glasses and takes it farcically far.

Don't want to clutter too much, I'm already eating downvotes, so I'll link:

https://news.ycombinator.com/item?id=46642003

	▲	chungy an hour ago \| parent [-]
		I have Windows 95 on a Pentium 120 MHz and calc.exe is instantaneous enough that it's probably much less than 300ms to launch. XP's calculator is hardly any different than 95. It's easy to believe that launching it on a Core 2 Duo of all things is also instant.

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jcelerier 2 hours ago | parent | prev [-]

yeah no. Ask musicians using computers - 50 milliseconds of latency between sound and movement is generally considered unplayable, 20 milliseconds is tough, below 10ms usually is where people start being unable to tell.