hi ,I have vivid100 installed 4 days now and pretty fed up all ready. average speed 26 to 44 Mbps and even dropped to 3 tonight . noticed rg6 coax outer layer damaged exposing inner shielding. all Roger testing by virgin reporting normal. anyone know if cable at wall could be causing problem intermittent.
If the copper shielding is exposed it will certainly degrade over time and it should be replaced. The outer plastic layer is very tough so it must have been severely abused.
But you have omitted the most important information. Are your speed measurements with an ethernet connection to the hub, in which case there is a problem with the VM broadband? Or are you measuring over WiFi, in which case you need to follow the WiFi advice posts to improve the coverage.