Josh Snyder hashbrowncipher

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

	#!/bin/bash

	# As the "bufferbloat" folks have recently re-discovered and/or more widely
	# publicized, congestion avoidance algorithms (such as those found in TCP) do
	# a great job of allowing network endpoints to negotiate transfer rates that
	# maximize a link's bandwidth usage without unduly penalizing any particular
	# stream. This allows bulk transfer streams to use the maximum available
	# bandwidth without affecting the latency of non-bulk (e.g. interactive)
	# streams.

	#!/bin/bash

	# As the "bufferbloat" folks have recently re-discovered and/or more widely
	# publicized, congestion avoidance algorithms (such as those found in TCP) do
	# a great job of allowing network endpoints to negotiate transfer rates that
	# maximize a link's bandwidth usage without unduly penalizing any particular
	# stream. This allows bulk transfer streams to use the maximum available
	# bandwidth without affecting the latency of non-bulk (e.g. interactive)
	# streams.