C.S. Lim chaelim

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

Original link: http://www.concentric.net/~Ttwang/tech/inthash.htm
Taken from: http://web.archive.org/web/20071223173210/http://www.concentric.net/~Ttwang/tech/inthash.htm
Reformatted using pandoc

Integer Hash Function

Thomas Wang, Jan 1997

last update Mar 2007

Plaintext 8 threads

Connections: 8		Haywire		Requests/sec:  57334.75
Connections: 8		Go		    Requests/sec:  42901.57
-------------------------------------------------------
Connections: 16		Haywire		Requests/sec:  71460.01
Connections: 16		Go		    Requests/sec:  71891.07
-------------------------------------------------------
Connections: 32		Haywire		Requests/sec:  78421.15
Connections: 32		Go		    Requests/sec:  89202.96

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

	apt-get install -y build-essential libx11-dev libgl1-mesa-dev libxext-dev perl perl-modules make
	cd /tmp
	wget http://byte-unixbench.googlecode.com/files/UnixBench5.1.3.tgz
	tar xzvf UnixBench5.1.3.tgz
	cd UnixBench
	./Run

	// The contents of this file are subject to the Mozilla Public License
	// Version 1.1 (the "License"); you may not use this file except in
	// compliance with the License. You may obtain a copy of the License
	// at http://www.mozilla.org/MPL/
	//
	// Software distributed under the License is distributed on an "AS IS"
	// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
	// the License for the specific language governing rights and
	// limitations under the License.
	//

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	Add-Type -Path "C:\Program Files (x86)\AWS SDK for .NET\bin\AWSSDK.dll"

	$region="ap-northeast-1"
	$accesskey="ACCESSKEY"
	$secretkey="SECRETKEY"
	$vaultname="myvault"
	$description="some binary file"
	$file="c:\hoge\target.bin"

	$endpoint = [Amazon.RegionEndpoint]::GetBySystemName($region)

	------- data ------ --------------------- load -------------------- - child -
	keys mem clients blocked requests connections
	577999 113.36M 1 0 0 (+0) 1
	748999 138.92M 1 0 1 (+0) 1
	922999 169.01M 1 0 2 (+1) 1
	1076999 211.63M 1 0 3 (+1) 1
	1216999 235.84M 1 0 4 (+1) 1
	1366999 253.78M 1 0 5 (+1) 1
	1520999 280.39M 1 0 6 (+1) 1
	1675999 307.18M 1 0 7 (+1) 1

	from requests_oauthlib import OAuth2Session
	from flask import Flask, request, redirect, session, url_for
	from flask.json import jsonify
	import os

	app = Flask(__name__)


	# This information is obtained upon registration of a new GitHub
	client_id = "<your client key>"