Archive for August, 2011

Power usage

I recently purchased the P3 Kill A Watt EZ (model 4460), and I have been using it to measure the power usage of a few items around my dorm room. I was originally inspired to do this from one of Jeff Atwood’s posts on power usage.

Desktop power usage

The first item I measured was my tower, the HP Compaq dc7900. It has the following specifications:

Intel Core 2 Duo E8400
Seagate 160GB
Western Digital 500 GB
ATI Radeon HD 2400 XT

The power measurements are as follows:

switched off 3 watts
on, idle 60 watts
on, BOINC at 50% 80 watts
on, BOINC at 100% 90 watts
suspend 4 watts

BOINC is free software that allows you to participate in a variety of distributed computing projects, and I used it to perform some CPU-intensive tasks for my testing. When I say BOINC at 50% and BOINC at 100%, I was utilizing BOINC preferences. It has an option, “On multiprocessor systems, use at most __% of the processors.” My system has 2 cores, so the 50% roughly corresponds to one core at full utilization, and 100% corresponds to both cores at full utilization.

It is interesting to compare these measurements to Jeff Atwood’s measurements. Two articles from 2005 give measurements of 118 w for a desktop, and 160 w for a server. My dc7900 specs are strikingly similar to Jeff’s 2005 desktop, and mine was a budget model purchased in 2009. For similar performance computers, we come to the conclusion that idle wattages have dropped by half in 5 years.

Probably more instructive is a comparison with Jeff’s 2011 Home Theater PC, which draws 22 watts idle. This is with a Mini-ITX board, and other power-saving goodies.

Monitor power usage

The next item I measured was my 22 inch widescreen monitor, an HP L2245wg. I learned that switched off and in power save mode, it uses the same amount of power, 3 watts. Switched on, it uses different wattage depending on the screen brightness.

on, 0 brightness 21 watts
on, 50 brightness 29 watts
on, 100 brightness 42 watts

Looking at the results, I was rather shocked that the power usage doubles when the brightness is turned up. It is better to keep your monitor’s brightness down, and this is best practice for monitors anyway.

Laptop power usage

Finally, I measured the power usage of my Eee PC 900, which I had recently installed Xubuntu 11.04 on. The power measurements are as follows:

idle at Xubuntu desktop, minimum brightness 16 watts
idle, wireless switched off 14 watts
idle, wireless on, maximum brightness 17 watts

Then, out of curiosity, I booted my Eee PC with Minix 3, since it is a small operating system designed for embedded use. I used version 3.1.2a for USB stick, which can be found in the MINIX previous versions. (The latest stable release is 3.1.8.) The power usage of this was 15 watts.

In summary, for my laptop, there is strikingly little difference between minimum brightness and maximum brightness. The difference between MINIX and a full-fledged operating system, Xubuntu, is minor as well.

It is also interesting to compare my Eee PC’s power usage with some of Jeff Atwood’s measurements. His Dell XPS M1330 (in 2008) used 20 watts idle, and his Dell Inspiron 300m (in 2006) used 15 watts idle. From this small amount of data, I can jump to the conclusion that, unlike desktops, laptops have not significantly improved their power usage.

Free software Firefox extensions

As a follow up to my previous post about free software, I decided to look at another type of software: browser extensions. Ubuntu 10.04 has Firefox 3.6.18 on it, and I added some extensions to bring the browser’s features a little up to date. I wanted to see if these extensions that I use are under a free software compatible license. The majority of them were, but some took more hunting than others to confirm this.

  • Advertising Cookie Opt-out Apache License 2.0 (Google code)
  • CookieCuller Mozilla Public License (
  • Download Statusbar This and CookieCuller stumped me until I looked at the legal notice at where it states “All code for each project hosted on the Site must be made available under the Mozilla Public License (MPL) unless otherwise noted on the project pages.”
  • Firebug From the extension home page, go to “Get Involved,” then to the page on google code. It uses the New BSD License.
  • FlashGot The only mention I could find is on the features page, where they say “Alternatively, since FlashGot is open source (GPL)…” This license could be more clearly stated.
  • GMarks Mozilla Public License version 1.1 (
  • Hide Menubar Mozilla Public License version 1.1 (
  • HTTPS-Everywhere GNU GPL version 2
  • New Tab JumpStart Mozilla Public License version 1.1 (Google code)
  • SQLite Manager Mozilla Public License version 1.1 (Google code)
  • Stop-or-Reload Button The developer’s home page is no longer active, but the extension’s page on states the license as BSD license. In newer versions of Firefox, this extension is no longer needed because the functionality is built in.
  • Ubuntu Firefox Modifications

Extensions without a free license:

  • Personal Menu (can’t find any documentation on the license, though the source code is publicized here)
  • Resizeable Textarea Trying to visit the home page on this one locks up the Add-ons window. In newer versions of Firefox, this extension is no longer needed because the functionality is built in.

Why I am writing this blog

After writing 3 posts, I think I am starting to get the hang of this blogging thing. I wanted to write about why I started blogging. I had been kicking around ideas for blogging in my head for quite some time, but I just wasn’t able to sit down and start it.

Taking Strengths Finder was the impetus I needed to start blogging. I took the test, and learned that my themes are input, deliberative, intellection, responsibility, and consistency. As I read through the strengths insights, something stuck out to me: three of my strengths mentioned the written word.

For example, the input theme includes the following insight: “You school yourself by reading, investigating, examining, experiencing, or receiving instruction in a subject.” As a follow-up to that, a suggested action was to share advice with others, or write about what I have learned. “Remember that you must be more than just a collector of information. … Make a point of identifying the facts and data that would be most valuable to others, and use this information to their advantage.”

I hope this blog is able to pull valuable information out of my own knowledge, and it is my hope that this information is of value to you.

The second reason I decided to jump in and start writing was because of an article I read on Coding Horror. How to Write Without Writing. Basically, writing and communication is the differentiator between a decent programmer, and an excellent programmer. Jeff Atwood’s article mentions two ways to train yourself to write: blogging, and cheating. Cheating in this case would be getting programmers to participate in Stack Overflow, where they learn to write by answering and asking questions.

I’ll try out blogging first. As I blog, my aim is to challenge myself to write longer, in-depth articles about things I have personally explored. I do not want to merely react to the latest tech topics. Jakob Nielsen’s article, Write Articles, Not Blog Postings, presents an excellent article about how to differentiate yourself by being proactive rather than reactive in your writing. We’ll see how this manifests myself in this blog.

Free software on my computer

I am intrigued by Richard Stallman’s free software philosophy, and while I would not consider myself a free software fanatic, I wanted to see how much non-free software I have on my primary computer.

My primary computer is an HP Compaq dc7900. I’m running Ubuntu 10.04 LTS as my main operating system. Right now I have the following non-free software programs on it, and I think this is a representative list for many GNU/Linux enthusiasts:

  • Graphics driver
  • A few games (Sauerbraten, Urban Terror, Assault Cube)
  • Skype
  • Flash plugin
  • Microsoft fonts

These packages can be easily found by using “Virtual RMS” (ubuntu package vrms), which basically gives advice that Richard M Stallman would give if he looked at the list of software on my computer.

Web browser extensions

Then I thought I should examine the list of web browser extensions I use regularly to see if they are open source.


Lately Chrome has been my main browser. I like Chrome’s default feature set, and I’ve only needed to add 3 extensions to it.

  • RSS Subscription Extension (by Google). I guess this really is by Google, because all the bug links on the extension info page link to, which redirects to the chromium google code project. This doesn’t make clear which license is used.
  • Super Full Feeds for Google Reader. This extension is simple. As soon as you visit the developer website, you can see that the code license is GNU GPL v3
  • Yet Another Google Bookmarks Extension. This developer page does not make clear what license is used.

The Social Factor

My boss’s boss at my summer internship loaned me “The Social Factor: Innovate, Ignite, and Win through Mass Collaboration and Social Networking,” by Maria Azua. (IBM Press, 2010)

The book focuses on some societal changes that are happening. The thesis of the book is that companies need to respond to these changes in order to succeed.

Ready for a history lesson? Chapter 1, “The Dawn of the Social Age,” covers some important background in communication technology. Each new communication technology (Radio, TV, Computer, Internet) had a faster adoption rate than the technology before it, and the result is a shift in how people communicate and share information. Chapter 2 discusses the implications for companies: employees are better able to share information if they can use these new technologies.

The next chapters discuss a number of social tools: blogs, wikis, tagging, Twitter, Facebook, and LinkedIn. As I read, I compared the tools the author discussed with tools that I have used. I am somewhat familiar with blogging, as I blog here and at I have contributed to Wikipedia. My summer internship is at Securian, and our company uses SocialText for several internal Wikis. I have a Facebook account, but I haven’t tried Twitter or LinkedIn yet. Reading this book definitely swayed me toward trying out these services.

On the other hand, after taking my Computing Ethics class at SCSU, I am increasingly cautious about sharing information online. A recent article I found through ACM confirmed this. The Obama administration released a roadmap that discussed cyber security, saying “The public is insufficiently aware of the risk of sharing information in cyberspace — which can affect personal and national security.” Whenever you’re using the internet, your every action is tracked and cataloged somewhere, and you don’t always have control over it.