A handful of homes in Cambridgeshire have tested 8 Gbps broadband speeds as part of a Virgin Media test.
Currently, only eight families in the village of Papworth are involved in the trial, but Virgin Media expects to extend that to 50 over time.
The technology it uses, passive ethernet network, offers the same speeds for downloads and uploads.
One analyst said it is important for fiber operators to isolate networks and ensure sufficient capacity.
8 Gbps speeds would allow users to:
- to download a 5GB high definition movie in five seconds
- download a 4GB ultra high-definition 20GB movie in 20 seconds
- download a 99GB video game in less than two minutes
- load 300 high-resolution photos of 3 GB in three seconds
"With our customers' internet usage volume nearly doubling each year, tests like this will ensure that we will be able to meet the demand for data hungry services in the future – whether by cable or full fiber," said Richard Sinclair, executive director of connectivity at Virgin Media.
He added that the trial was intended to look to the future "until the next decade and beyond."
Independent telecoms analyst Paolo Pescatore is not convinced that there is still an appetite for such speeds.
"There has been a kind of fiber frenzy recently and there is a clear case to upgrade to fiber, but people will notice the difference [between 1Gbps and 5Gbps]?" he asked.
That said, it was important for all providers to find ways to prepare their networks for the future, Pescatore said.
"It's a natural progression for Virgin Media to extend its network and allow for more speed and capacity, and this used the existing infrastructure so it did not have to dig roads," he said.
"Providers need to be smart about their investments."
Virgin Media's UK network currently runs more than 14 million installations using a combination of cable and fiber optics.
The company has been criticized by some for not addressing the digital divide and for concentrating its network in cities and more profitable cities rather than extending it to more rural areas.
Last year it joined Need4Speed to launch ultrafast services for 4,000 facilities in Test Valley, Hampshire, but admitted that it is unlikely to reach very rural areas.
Rival, which relies on its former copper network to carry many of its broadband connections from street booths to consumer homes, has promised full fiber connections to three million homes by 2020. Of these, 70,000 will be in rural areas .
In February last year, another fast fiber company, Hyperoptic, tested speeds of up to 10 Gbps in a house in East London, which is the fastest in the UK using an existing network rather than a dedicated line.