Have you tried going to about:config
and enabling OMTC + e10s + APZ? Firefox works very well on my FreeBSD machines.
layers.acceleration.force-enabled=true
layers.async-pan-zoom.enabled=true
layers.offmainthreadcomposition.testing.enabled=true
gfx.xrender.enabled=false
browser.tabs.remote.autostart=true
Post your response
If you write a response on your website, mark it up with h-entry and let me know the URL: