Augustin Lacour austil

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

#HTML presentation tools

There are many HTML presentation tools and they are all created for slightly different reasons. Here's an overview. Please let me know if I forgot any.

##CSSS

CSS-based SlideShow System

	// Lack of tail call optimization in JS
	var sum = function(x, y) {
	return y > 0 ? sum(x + 1, y - 1) :
	y < 0 ? sum(x - 1, y + 1) :
	x
	}

	sum(20, 100000) // => RangeError: Maximum call stack size exceeded

	// Using workaround