Flash is anathema to green browsing, says study

Flash sites draw more power

Web sites using dynamic technologies such as Adobe's Flash represent a significant drain on computing power, according to an informal study conducted by a security expert.

Robert Hansen, founder of the security website SecTheory, visited a variety of web sites using the Firefox web browser and examined the effect of the sites using the Kill-A-Watt power measurement device in combination with Microsoft Windows' Task Manager utility, which measures the processes running on a PC.

Hansen tried surfing pages using Firefox on its own, and then installed the NoScript and AdBlock plug-ins, which prevent the browser running the JavaScript dynamic programming language that is used to make sites more interactive, and also block rotating advertising banners delivered using the Flash multimedia player developed by Adobe.

Hansen analysed the 100 most visited sites on the web, and then focused on the 10 that caused a PC to use the most power. He found that the plug-ins reduced the power consumption of a PC viewing the sites from 56.76 watts to 45.1.

"To put that in perspective, that's the same savings as it costs to run an 11 watt compact fluorescent light," Hansen said.

Flash-based banner ads that rotate once a page has been loaded caused sites displaying them to continue drawing power long after they had been loaded, said Hansen.

He added that the study was not strictly scientific because of variations in amperage over time, but nevertheless conducting the tests repeatedly provided useful evidence that these dynamic multimedia technologies required more energy.

"It does appear that it would be possible to surf in a 'green' manner," Hansen said in the report. "That is, reducing the amount of client side scripting that runs within the browser, returning the browser to a static page while not viewing the page or closing the browser when not in use, and using power save modes built into the operating system. While the differences may appear to be minor in power usage, power consumption does add up over time."