MS Claims Link Between Browser Choice, Battery Life

Reducing mobile power consumption has been a top priority of the PC industry for years. Much of the work in this area has focused on hardware, but a recent post from Microsoft's IE blog raises the question of whether or not browser choice can make a difference in battery life*. It's not a question people would've considered for most of the past decade, but the advent of smartphones, hardware-accelerated browsers, and even netbooks have changed the way people prioritize battery life as a must-have feature.

Microsoft tested Chrome 10, Firefox 4, IE9, Opera 11, and Safari 5 in the following scenarios:
  • Windows 7 without any browsers running (provides baseline).
  • Browsers navigated to about:blank (power consumption of the browser UI).
  • Loading one of the world’s most popular news Web sites (common HTML4 scenario).
  • Running the HTML5 Galactic experience (representative of graphical HTML5 scenario).
  • Fish swimming around the FishIE Tank (what test is complete without FishIE).
Data for the individual tests can be found at the MSDN website; we've elected to graph the final battery test results. A number of Microsoft's graphs don't use zero as a starting point, thus allowing the company to make minor differences in performance appear significant.

Microsoft's total battery life graph, regraphed from zero.

Microsoft's test results imply that using Opera, Safari, and Chrome 10 is equivalent to pulling a few cells out of one's battery. That's not a conclusion we're willing to validate, particularly since Microsoft doesn't disclose certain pertinent test facts. Power consumption tests have become more important as users migrate to smaller, hand-held devices; evaluating the browser's impact is another logical step upon the same path.

Unfortunately, it's also significantly more complicated. The IE bloggers state: "We focused on making IE fast - the quicker a browser can perform an action the less power the browser will consume. We focused on using modern PC hardware to accelerate IE - natively using the specialized hardware decreases power consumption. We focused on idle resource usage - the browser shouldn’t be doing work and consuming power when the user isn’t interacting with the browser. And we focused on following device power management guidance - the browser should respect the guidance of the hardware manufactures."

The first assumption—namely that faster calculation saves power—is far from universally true. It's also important to isolate what plugins or third-party utilities might be causing Browser A to draw far more power than Browser B. The authors themselves note that Opera uses markedly more power than any other browser in one test because "Opera changes the system timer resolution from the default 15.6ms to 2.5ms which prevents the CPU from entering low power states." This type of error makes it difficult to draw an apples-to-apples comparison, though it presumably also pressures Opera (or any browser developer) to patch their code.