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@jboner
jboner / latency.txt
Last active November 9, 2025 02:40
Latency Numbers Every Programmer Should Know
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
@andreyvit
andreyvit / tmux.md
Created June 13, 2012 03:41
tmux cheatsheet

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

@spion
spion / a-warning.md
Last active April 19, 2025 05:17
C++ versus V8 versus luajit versus C benchmark - (hash) tables

Warning

This benchmark has been misleading for a while. It was originally made to demonstrate how JIT compilers can do all sorts of crazy stuff to your code - especially LuaJIT - and was meant to be a starting point of discussion about what exactly LuaJIT does and how.

As a result, its not indicative of what its performance may be on more realistic data. Differences can be expected because

  1. the text will not consist of hard-coded constants
@iomz
iomz / HadamardMatrixMaker.py
Created July 19, 2012 14:29
Takes an interger n for 2^n x 2^n Hadamard matrix
#!/usr/bin/env python
# Takes an interger n for 2^n x 2^n Hadamard matrix
import numpy as np
import sys
def recursiveKronecker(k, hmat):
if 2**(k-1) == 1:
return hmat
else:
@ibeex
ibeex / foo.log
Created August 4, 2012 13:46
Flask logging example
A warning occurred (42 apples)
An error occurred
@piscisaureus
piscisaureus / pr.md
Created August 13, 2012 16:12
Checkout github pull requests locally

Locate the section for your github remote in the .git/config file. It looks like this:

[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = [email protected]:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

@igrigorik
igrigorik / igvita.har.json
Created August 28, 2012 05:16
Sample HAR capture of igvita.com homepage
{
"log": {
"version": "1.2",
"creator": {
"name": "WebInspector",
"version": "537.1"
},
"pages": [
{
"startedDateTime": "2012-08-28T05:14:24.803Z",
@amaxwell01
amaxwell01 / interviewitems.MD
Created September 15, 2012 14:17
My answers to over 100 Google interview questions

##Google Interview Questions: Product Marketing Manager

  • Why do you want to join Google? -- Because I want to create tools for others to learn, for free. I didn't have a lot of money when growing up so I didn't get access to the same books, computers and resources that others had which caused money, I want to help ensure that others can learn on the same playing field regardless of their families wealth status or location.
  • What do you know about Google’s product and technology? -- A lot actually, I am a beta tester for numerous products, I use most of the Google tools such as: Search, Gmaill, Drive, Reader, Calendar, G+, YouTube, Web Master Tools, Keyword tools, Analytics etc.
  • If you are Product Manager for Google’s Adwords, how do you plan to market this?
  • What would you say during an AdWords or AdSense product seminar?
  • Who are Google’s competitors, and how does Google compete with them? -- Google competes on numerous fields: --- Search: Baidu, Bing, Duck Duck Go
@omz
omz / FileTransfer.py
Last active September 6, 2024 01:50
File Transfer script for Pythonista (iOS)
# File Transfer for Pythonista
# ============================
# This script allows you to transfer Python files from
# and to Pythonista via local Wifi.
# It starts a basic HTTP server that you can access
# as a web page from your browser.
# When you upload a file that already exists, it is
# renamed automatically.
# From Pythonista's settings, you can add this script
# to the actions menu of the editor for quick access.
gnome-cups-manager
------------------
Once upon a time there was a printer who lived in the woods. He was a
lonely printer, because nobody knew how to configure him. He hoped
and hoped for someone to play with.
One day, the wind passed by the printer's cottage. "Whoosh," said the
wind. The printer became excited. Maybe the wind would be his
friend!