Computer vs. Human Time

I got interested in comparing the experience of human time to computer time. I didn’t double verify the exact numbers below. Take it with a grain of salt. I think it’s interesting, if only from a sci-fi perspective.

Computer Information	Computer Time	Human Time	Human Information
1 CPU cycle	0.3 ns	1 s	Add two small numbers in your head
Level 1 cache access	0.9 ns	3 s	A number scribbled in the margin of a piece of paper
Level 2 cache access	2.8 ns	9 s	Something written a few pages away
Level 3 cache access	12.9 ns	43 s	A term you have to look up in the index at the back of the book
Main memory access	120 ns	6 min	Something you wrote in your notebook, but aren’t sure exactly where
Solid-state disk i/o	50 µs	2 days	A book from the local library
Rotational disk i/o	1 ms	1 month	A book you have to research, find, order, and have mailed to you
Internet: US East to West	40 ms	4 years	Something you have to get a college degree to learn
Internet: North America to Europe	81 ms	8 years	Something you learn after starting your career
Internet: North America to Australia	183 ms	19 years	Something you learn after a career spent in the field
Virtual OS reboot	4 s	423 years	It takes generations of people to figure this out
Physical system reboot	5 m	32 millennia	Since the time people were hunter/gatherers
Modern home computers, 1980s to 2020s	40 y	40,000 millennia	Longer ago than the Earth itself even exists

I’m not exactly sure where the original source for this is, but here is an example: Here’s a neat trick for understanding how long computer processes take.