The ‘Super HD’ Effect

On September 26, Netflix tweaked a policy that previously restricted access to its “Super HD” library of 1080p and 3D titles to to subscribers who got their broadband service from ISPs that were members of Open Connect, Netflix’s private content delivery network (CDN).

Netflix’s Super HD streams are delivered at a bit rate of up to 5.8 Mbps, versus 3.85 Mbps for Netflix’s not-as-super HD streams, Sandvine noted in its latest bandwidth study, released on Monday (November 11).

Although Super HD streams are bigger and require more throughput, more time is needed to determine how Netflix’s new Super HD-for-all policy is affecting broadband networks. Sandvine’s initial analysis shows that the impact can vary by ISP.

Sandvine compared Netflix bandwidth of two U.S. fixed access networks during the first few days of the policy change. While Network #1 showed no significant change in total Netflix volume, Network #2 saw a 10% to 15% boost in Netflix traffic, and a 2% to 5% increase in total traffic during peak hours.

This discrepancy could be due to the service levels offered by each ISP. Sandvine noted that Network #1 offered several plans below the 7 Mbps minimum required for Super HD, while the ISP operating Network #2 does not. It's also possible that two networks studied could be peering with different CDNs or the CDN at Network #1 “was already at maximum capacity,” Sandvine said.

But there are other variables in play. Only a limited amount of Netflix content is offered in Super HD, and a subset of devices (PlayStation 3, Apple TV with 1080p, Google Chromecast, Roku with 1080p, the Nintendo Wii U and the TiVo Premiere DVR, among them) are capable of streaming Super HD content.

So, the bottom line is that there’s not enough data to really know how of Netflix’s new Super HD policy is impacting network bandwidth.

“Even with device limitations in place, the lifting of ISP restrictions for Super HD content is a great step towards making a ubiquitous consistent experience for all subscribers,” Sandvine said. “But as seen in the charts…a longer view will be required to fully understand how it will impact ISPs.”