Why is Firefox CPU usage high when viewing globe

Hi,

I have done the following steps:

Installed cesium and node.js and started node to server up maps.
Navigated to localhost:8080 in firefox - Version 46.0.1
firefox consumes approx. 75% CPU. Verified that “Use hardware acceleration when available” is enabled in the browser.

In chrome the CPU sits at about 15%.

I am running Fedora release 23.

Question: Why does firefox consume so much CPU?

Regards,

Ram

I’m seeing something similar when running in a VM. Cesium sitting idle on Chrome: <5% CPU. Cesium sitting idle on Firefox: 25% CPU.