У вашего броузера проблема в совместимости с HTML5
Recorded through Shadowplay with 3-5 fps deficit. Secondly CPU is the bottleneck in this game at ultra settings so to get steady fps, some settings have to be compromised!
PC specification:
1) I7 3770k 4.5 ghz
2) Gigabyte z77-d3h
3) Gskill ripjaws 2400mhz- 16gb
4) Gigabyte gtx 1060 6gb gaming extreme
P.S The refresh rate of the monitor is locked at 66fps