Do you know how much your computer can do in a second? (2015)
I like to test people’s intuition of computer power by asking them how many multiplications their phone or PC can make in the time it takes light to cross the room.<p>The way to estimate this is that light takes 3ns to go 1m. If the room is 10m wide, that’s 30ns. At typical frequencies that’s 100 clocks. With, say, 8 cores that’s 800 steps. At each step a core can retire about 8 multiplies using AVX vector instructions. The estimate of 6,400 multiplications is actually very conservative because you also have the GPU! Even low end models can put out hundreds of thousands of multiplications in 30ns. High end models can do about a million.<p>When asked, most people estimate “1 to 10”. Even programmers and IT professionals do not have a mental model of how fast computers really are.