It's all about these tests that IE11 appear to use 1/2 of the CPU while Chrome use double CPU usage. All hardware accelerator enabled in Windows 8.1.
http://phaser.io/examples/v2/demoscene/atari-intro
http://phaser.io/examples/v2/games/starstruck
http://phaser.io/examples/v2/demoscene/atari-intro
http://phaser.io/examples/v2/games/starstruck