Important numbers in computer science

Post date: Oct 07, 2011 8:6:15 PM

Part Zero: The Antediluvian Version?

Part One: The Original

Teach Yourself Programming in Ten Years by Peter Norvig

Remember that there is a "computer" in "computer science".

Know how long it takes your computer to

• execute an instruction,

• fetch a word from memory, with and without a cache miss,

• read consecutive words from disk, and ]seek to a new location on disk.

Answers

Approximate timing for various operations on a typical PC:

Part Two: Updated Version

by Jeff Dean Computing Performance "Numbers Everyone Should Know".

Where

• 1 ns = 10^-9 seconds

• 1 ms = 10^-3 seconds

Also see: Slides #1 (Stanford) and Slides #2 (Cornell 2009).

Found via Quora: What are the numbers that every computer engineer should know according to Jeff Dean.

Part 3: Miscellania

For more good work by Jeff Dean, in the specific context of his employer (at the time, perhaps now) see Underneath the covers at Google: Current systems and future directions, presented at Google I/O 2008. Petru Paler's blog post (June 16, 2008) analyzed that same presentation. Two final documents for those wishing to know more basics are

1. Serious: What every computer scientist should know about floating-point arithmetic by David Goldberg, published in the March, 1991 issue of Computing Surveys (ACM).

2. Less serious: The Case of the 500 Mile Email, by Trey Harris. With follow-up FAQ's, or more accurately, "the answer key".

Footnote: I think that Trey Cuthrell was asking or trying to answer a similar very basic question, along the lines of "Important numbers in systems administration" on Quora, although it went unnoticed by all, including myself, until after the fact. See