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@hellerbarde
hellerbarde / latency.markdown
Created May 31, 2012 13:16 — forked from jboner/latency.txt
Latency numbers every programmer should know

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

@niksumeiko
niksumeiko / git.migrate
Last active July 10, 2024 14:29
Moving git repository and all its branches, tags to a new remote repository keeping commits history
#!/bin/bash
# Sometimes you need to move your existing git repository
# to a new remote repository (/new remote origin).
# Here are a simple and quick steps that does exactly this.
#
# Let's assume we call "old repo" the repository you wish
# to move, and "new repo" the one you wish to move to.
#
### Step 1. Make sure you have a local copy of all "old repo"
### branches and tags.
@avafloww
avafloww / PhpJava.java
Last active June 13, 2024 07:36
This snippet of code is syntactically valid in both PHP and Java, and produces the same output in both.
/*<?php
//*/public class PhpJava { public static void main(String[] args) { System.out.printf("/*%s",
//\u000A\u002F\u002A
class PhpJava {
static function main() {
echo(//\u000A\u002A\u002F
"Hello World!");
}}
//\u000A\u002F\u002A
PhpJava::main();