The slowest street for broadband in Wales has a more than 50 times slower connection speed than the area with the fastest download speeds.
Llanybydder in Carmarthenshire - with average download speeds of 1.28Mbps - has the slowest speeds in Wales according to consumer group uSwitch.
This is 53 times slower than Clare Walk, Pembroke, which boasts average speeds of 67.79Mbps.
The average UK speed is 54.2Mbps, yet a fifth (19%) of homes struggle with speeds of less than 10Mbps and one in ten (9%) suffer from speeds as slow as 5Mbps.
Seven of the ten UK streets struggling with the slowest speeds are able to get superfast fibre broadband.
uSwitch.com urges consumers to check what speeds are possible in their postcode and change providers to get a better deal.
In Penffordd it would take more than 11 hours to download a two-hour HD film on Netflix and at least four hours to download a 45-minute HD TV show.
By contrast, on Clare Walk it would take less than 13 minutes to download the same film and less than five minutes to download the same TV show.
According to the research, uSwitch says is based on more than 122,845 'real world' speed tests run by broadband users over the last year, the number of broadband users enjoying faster speeds is growing. Nearly four in ten users (38%) now get speeds of more than 30Mbps, up from less than a quarter (22%) four years ago.
The slowest streets for broadband speeds in Wales are ranked below:
Penffordd, Llanybydder, Carmarthenshire
Penrhos, Raglan, Usk
Hutton Roof, Penrith
Tynygraig, Ystrad Meurig
The top five fastest streets in Wales are:
Clare Walk, Pembroke
Cross Park, Pennar, Pembroke Dock
Brynhedydd, Mathry, Haverfordwest
Surgery Road, Blaina, Abertillery
Y Deri, Llantwit Fardre, Pontypridd