Here are the scores I get on HTML5 test page using Firefox 51.0.1:
Vista SP2 32 bit : 469 / 555
XP SP3 32 bit : 471 / 555
In Vista the beacon (under "communicaton" results) seems disabled. In XP it's enabled. Both by default, I think. Not sure if I changed a setting related to this function.
EDIT: I checked the settings in Firefox/Vista via about:config. "beacon.enabled" was user defined and set as false. Cannot remember which setting was that. However my question is still valid.
Edited by devilus, 02 February 2017 - 02:47 AM.