You seriously get 8 Gbps on anything else than torrents? I get 400 Mbps in Canada and there so many time where I download and I hardly get more than 100 Mbps... Steam and torrents are pretty much the only times I get my full 400 Mbps.
That would mean the servers don't give you more than 100, but your provider does honestly provide you a 400 Mbps channel.
I max out at around 1 Gbps on steam, although I think I might be bottlenecked by my cpu for decompression. Servers that allows clients to pull 8Gbps are very rare.