I have only 2 responses left - either:
! or
!
Seriously, though, if you're not using Chrome, nw.js or Edge then you need to upgrade... Turn off all other programs on your computer - if you're running Unity, Blender or have 30 tabs of GIMP open then that could be the cause of your trouble. If not, try pressing f12 in Chrome and record some timeline to see what might be causing your frame drops. If none of that works, you could post a capx of your test for others to try...