[MovedGoalPosts]

I can see you are using the ADSL service from Virgin. As with most broadband services they are contended, i.e. shared, with other users. Thus what people nearby are doing will affect the bandwidth available to you. It's to be expected that at Peak hours more users will be on line and thus you all slow each other.

With ADSL your service speed is also affected by the quality of your phone line connection, and the distance from the exchange.

Other ADSL based ISPs will also be prone to contention issues, but depending on their popularity, and who is doing what, this could be better or worse in your local area.