While ISP Virgin today launched its fiberoptic network, with the hopes of becoming the fastest network in the United Kingdom, the firm's throttling practices will likely remain in place.

Virgin has announced that its 50 Mbps tier will cost £51 per month alone, or £35 if paired with an £11 per month Virgin landline.

Virgin's tiered broadband service formerly offered packages of 2, 10, and 20 Mbps maximum speeds for between £4.50-£10 a month. These top speeds, however, are reputed to be far from the actual speeds attained in the field, as Virgin is known to cap a user's throughput depending on usage during peak hours.

For example, users of the top tier "XL" service who download over 3 GB during peak hours have their 20 Mbps speed throttled back to 5 Mbps downstream and 256 Kbps upstream.

Throttling is a major complaint for Virgin subscribers who consume movie files or play online games, as both activities invariably lead to a slower connection. Therefore, rather than market its "mother of all broadband" connections to gamers or movie fanatics, it markets its connections by the length of time they take to download a single 5 MB music track.

For the XL tier, it claims it only takes 2 seconds to get a song. At this speed, a user could theoretically reach his peak download limit in 21 minutes (I say theoretically because this would involve downloading 614 songs, or roughly 50 albums at a single shot, an extremely large amount for most casual downloaders.)

The service was tested this year in Kent, and will continue its UK rollout over the next six months.