hermantolim

/*! 
 * quantize.js Copyright 2008 Nick Rabinowitz.
 * Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
 */

// fill out a couple protovis dependencies
/*!
 * Block below copied from Protovis: http://mbostock.github.com/protovis/
 * Copyright 2010 Stanford Visualization Group
 * Licensed under the BSD License: http://www.opensource.org/licenses/bsd-license.php

hermantolim

"use strict";
define(["require", "exports"], function (require, exports) {
    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Browser compatibility definitions
    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Private state
    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    var qrcodescanner = null;

hermantolim

Keybase proof

I hereby claim:

• I am hermantolim on github.
• I am hermantolim (https://keybase.io/hermantolim) on keybase.
• I have a public key ASBq4cdchPkmQJVSRUZ7Nw2O9xJZvfOajlzuP0M2ubjIzAo

To claim this, I am signing this object:

hermantolim

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

hermantolim

source: https://serverfault.com/questions/685289/software-vs-hardware-raid-performance-and-cache-usage

In short: if using a low-end RAID card (without cache), do yourself a favor and switch to software RAID. If using a mid-to-high-end card (with BBU or NVRAM), then hardware is often (but not always! see below) a good choice.

Long answer: when computing power was limited, hardware RAID cards had the significant advantage to offload parity/syndrome calculation for RAID schemes involving them (RAID 3/4/5, RAID6, ecc).

However, with the ever increasing CPU performance, this advantage basically disappeared: even my laptop's ancient CPU (Core i5 M 520, Westmere generation) have XOR performance of over 4 GB/s and RAID-6 syndrome performance over 3 GB/s over a single execution core.

The advantage that hardware RAID maintains today is the presence of a power-loss protected DRAM cache, in the form of BBU or NVRAM. This protected cache give very low latency for random write access (and reads that hit