Alix Axel alixaxel

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

In a perfect world, where things are done well, not just quickly, I would expect to find the following when joining the company:

Documentation

Accurate / up-to-date systems architecture diagram
Accurate / up-to-date network diagram
Out-of-hours support plan
Incident management plan

	( function ( window, undefined ) {
	var Aloha = window.Aloha \|\| ( window.Aloha = {} );

	Aloha.settings = {
	logLevels: { 'error': true, 'warn': true, 'info': true, 'debug': false, 'deprecated': true },
	errorhandling: false,
	ribbon: false,
	locale: 'en',
	floatingmenu: {
	width: 630,

	var page = require('webpage').create();

	page.open('http://www.website.com/', function (status) {
	if (status === 'success') {
	captureAjaxResponsesToConsole();
	}
	});

	function captureAjaxResponsesToConsole() {
	// logs ajax response contents to console so sublime's onConsoleMessage can use the contents

	# A class-based template for jQuery plugins in Coffeescript
	#
	# $('.target').myPlugin({ paramA: 'not-foo' });
	# $('.target').myPlugin('myMethod', 'Hello, world');
	#
	# Check out Alan Hogan's original jQuery plugin template:
	# https://github.com/alanhogan/Coffeescript-jQuery-Plugin-Template
	#
	(($, window) ->

	// Usage : less2stylusDir('../src/css/');

	var fs = require('fs');

	// this less 2 stylus conversion script make a stylus easy to read syntax
	// - let the braces
	// - replace the @ for var as $
	// - let semicolons

	function less2stylus(less)

	<?php
	// In order to solve the problem of a backslash followed by a double quote
	// (https://bugs.php.net/bug.php?id=43225), I wrote a new function.

	// This is compatible with fputcsv() except for the additional 5th argument $escape,
	// which has the same meaning as that of fgetcsv().
	// If you set it to '"' (double quote), every double quote is escaped by itself.

	// The version I posted on http://php.net/manual/en/function.fputcsv.php has a little bug.

	<?php

	require('relations.php');

	$database = 'relations';

	header('Content-Type: text/plain; charset="UTF-8"');

	$relations = relations($database);

	<?php
	/**
	* Create a web friendly URL slug from a string.
	*
	* Although supported, transliteration is discouraged because
	* 1) most web browsers support UTF-8 characters in URLs
	* 2) transliteration causes a loss of information
	*
	* @author Sean Murphy <[email protected]>
	* @copyright Copyright 2012 Sean Murphy. All rights reserved.

	import numpy as np
	from scipy.sparse import csc_matrix
	import random

	def column(matrix, i):
	return [row[i] for row in matrix]

	def pageRank(G, s = 0.85, maxerr = .001):
	"""
	Computes the pagerank for each of the n states.