We are constantly trying to improve our web applications performance to gain speed, lower the load on the clusters and thus being able to attend to even more users but have you ever thought about how these improvements can aid Global Warming?
For years optimization techniques such as Caching in many levels (Disk/Memory), Compression, Clustering and other were developed to acheive greater performance.
Global Warming is there for years and is getting worse every year but it seems that movements under IT has begun in order to create greener solutions. Many hosts such as Dreamhost (which we’re proud of being our hosting company) have already started their effort in reducing or even neutralizing their Carbon Footprint and now developers can help on their side too.
The Concept
Well, we don’t have to go too far to realize where optimization crosses paths with sustainability. It’s simple, it’s all about electricity (power) saving.
Again, it’s all about electricity. Every single bit minor instruction spends a very little piece of energy that goes through the processor and memory I/O operations and spends some little more sending data over the ethernet ports.
Let’s go from the beginning. The user has requested a website, the request goes through all the routers and switches in the way to the requisition.
NOTE: We are not considering this power consumption because it is not dependent on the application’s optimization.
Here is where optimization makes the difference: the way back.
Larger image or source files will take more CPU cycles to be processed, more Disk usage and more space allocated in memory. Then these big files have to be sent to the client and if you have many files this means more HTTP connections and headers being sent.
Techniques such CSS Sprites (heavily used by Google and other big companies) aid to reduce the HTTP Connections between the server and the client.
Each HTTP connections contains not only the file’s data but it is preceded by header data with the file’s type, modified date and some other info so two square 20px images are bigger than one rectangular 40px per 20px image (the two 20px square images side by side).
Then the requested files come from the server to the client by all the router and switches in-between them spending more power in transmission until it gets to its destiny where will consume more power to be rendered by client browser’s engine and window manager (Windows, Gnome, Kde etc).
How to collaborate?
Optimize your software. Yahoo‘s YSlow and Google‘s Page Speed are great kickstarts. You can also check our articles on caching.
As all great saving and recycling, results will only take place with everyone’s effort. These taken under huge proportions can result in great saving and thus more breathe to our planet.
Think green.
Other considerations under power saving on software development
In this 2007 article, Mark Ontkush showed his study where dark-pallete-themed web applications required less energy from users’ CRT monitors.
“an all white web page uses about 74 watts to display, while an all black page uses only 59 watts. I thought I would do a little math and see what could be saved by moving a high volume site to the black format.”
Mark Ontkush
And then the results came when he compared to traffic reports of huge websites such as Google:
Take at look at Google, who gets about 200 million queries a day. Let’s assume each query is displayed for about 10 seconds; that means Google is running for about 550,000 hours every day on some desktop. Assuming that users run Google in full screen mode, the shift to a black background [on a CRT monitor! mjo] will save a total of 15 (74-59) watts. That turns into a global savings of 8.3 Megawatt-hours per day, or about 3000 Megawatt-hours a year. Now take into account that about 25 percent of the monitors in the world are CRTs, and at 10 cents a kilowatt-hour, that’s $75,000, a goodly amount of energy and dollars for changing a few color codes.
Mark Ontkush
Black is the new black!
Unfortunately, dark-themed websites tend to be less accepted by the users, and some have even reported that white characters tend to blur by reading stress while reading an extensive text.
And you developer? What are you doing to save the world?