"IE9/IE10 also led the way in terms of fast, pervasive hardware acceleration for browser rendering - while Firefox and Chrome had HW accel first in certain scen

"IE9/IE10 also led the way in terms of fast, pervasive hardware acceleration for browser rendering - while Firefox and Chrome had HW accel first in certain scenarios, IE was early to the game when it comes to using hardware to render entire pages." That would explain why the power draw for other browsers was fluctuating depending upon websites surfed and IE seemed kind of consistent.