fsevenm

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

fsevenm

#!/bin/bash

# Thanks goes to @pete-otaqui for the initial gist:
# https://gist.github.com/pete-otaqui/4188238
#
# Original version modified by Marek Suscak
#
# works with a file called VERSION in the current directory,
# the contents of which should be a semantic version number
# such as "1.2.3" or even "1.2.3-beta+001.ab"