devel.rst
author Oleksandr Gavenko <gavenkoa@gmail.com>
Tue, 05 Dec 2017 23:51:54 +0200
changeset 2209 6faf149a4f4c
parent 1912 8b81a8f0f692
child 2228 837f1337c59b
permissions -rw-r--r--
Show difference.

.. -*- coding: utf-8; -*-

=============
 Development
=============
.. contents::
   :local:

Numbers everyone should know
============================

 * L1 cache reference 0.5 ns
 * Branch mispredict 5 ns
 * L2 cache reference 7 ns
 * Mutex lock/unlock 100 ns
 * Main memory reference 100 ns
 * Compress 1K bytes with Zippy 10,000 ns
 * Send 2K bytes over 1 Gbps network 20,000 ns
 * Read 1 MB sequentially from memory 250,000 ns
 * Round trip within same datacenter 500,000 ns
 * Disk seek 10,000,000 ns
 * Read 1 MB sequentially from network 10,000,000 ns
 * Read 1 MB sequentially from disk 30,000,000 ns
 * Send packet CA->Netherlands->CA 150,000,000 ns