Faster Connectivity Needed for Increasing Storage Requirements and 4K Video
The demand for faster response time, combined with consumers’ bottomless appetite for storage and higher resolution video, drives the need for faster wired interfaces like 10G USB and Thunderbolt 2.
The fastest PC interface in the world, Thunderbolt 1 at 10 Gbps, has shipped in tens of millions of Apple PCs and a few million Windows PCs. While Thunderbolt 1 in PCs has not reached the ubiquity of USB 3.0 in consumer products, Thunderbolt 2, running at 20 Gbps, may be positioned for wider use after its launch in Apple MacPros later this year. USB, however, has already been broadly adopted beyond the PC in many consumer products. For example, televisions use USB both outside and inside the TV for post-silicon feature additions like storage or wireless connectivity. Thunderbolt, a closed, proprietary standard, has remained only in PCs. As storage prices go down, and use of 4K video increases, consumer demand for the faster connectivity that Thunderbolt 2 and USB can provide will increase.
Falling Storage Prices and Increasing Storage Needs
NAND flash prices have fallen precipitously, and will continue to drop 33-40 percent per year while its performance increases. By 2017, 100GB of fast NAND flash memory is expected to drop to $9, from its current cost of $48. One element that is driving the widespread use of NAND flash storage is the growth of HD and 4K video recording on phones and cameras, as well as its use as the playback on a variety of devices. 4K video supports 4,096 x 2,160 pixels per frame, or about 8.9 megapixels per frame, which is about 4 times the pixels in 1080p TVs—requiring four times the storage capacity above 1080p quality. A 4K movie will use 100GB for a two-hour movie, or four times the size of a 1080p Blu-ray movie at 27GB per disk. Consumers recording 4K video with GoPro cameras or the Qualcomm Snapdragon 800-based phones that are available now will need more storage to hold their hours of 4K video.
The Trend in Consumer 4K Video
In 2012, 4K TVs entered the consumer market. In 2013, 4K will enter millions of homes in Sony’s new PS4 game consoles, which will be used not only for games, but also for movies. While the PS4 supports the playback of Blu-ray discs, 4K does not have a disc standard. At 100GB per movie, only two options exist for delivery to the home: downloading from the Internet or renting (from a kiosk or via mail). Downloading 4K movies is possible, but downloading a 100GB 4K movie over typical cable modem speeds will require between two and twenty hours per movie. Compressing the movie will help reduce this time, but to maintain high quality, file sizes will likely remain too high to adequately reduce the download time. Most consumers will not have the fiber-to-home connectivity at Gigabit per second speeds necessary for reasonable download times. Renting a movie on a content-protected flash drive at a kiosk or via mail is more likely. In fact, the dropping prices of storage make flash drive delivery more likely because USB is well-understood by both consumers and product makers.
10G USB or USB 3.0 for 4K Movies
At an effective throughput of 4 Gbps, USB 3.0 allows for the transfer of movies to a drive in about five minutes. This isn’t fast enough for someone to walk up to a kiosk, insert a flash drive and download a movie, but if the kiosk holds an inventory of pre-loaded USB 3.0 drives, it would work. The limitation of USB 3.0 is the speed to stream the video off the drive for viewing. A compressed 4K video requires 8.9 Gbps, which is faster than the USB 3.0 standard can support. Therefore, streaming videos at the fastest speeds and with the lowest amount of compression will require a new generation of USB flash drives that support the 10 Gbps data rates, which is called "10G USB" until the official name is announced. 10G USB will be better for both the storage and streaming of video because of its ubiquity and speed. For immediate transfer and storage of a 4K movie, 10G USB enables movies to be transferred in 2.5 minutes, which is closer to the “instant on” that consumers expect. Also, after bringing the 10G USB drive home, it’s more likely the consumer will understand how to use it and be able to simply plug it in to a 4K player or a TV. USB 3.0 cannot support 4K streaming without substantial compression which reduces overall viewing quality, but 10G USB can. The PC requirements for streaming video vary, so both 10G USB and Thunderbolt 2 are needed for PCs.
10G USB and Thunderbolt 2 for 4K Displays
Thunderbolt 2 will support 20 Gbps for PCs and notebooks to stream both video and data simultaneously over a single cable. Thunderbolt 2 on MacPros allows for the connection of multiple 4K monitors and superfast Thunderbolt 2 solid-state drives (SSDs). Thunderbolt 2 will also allow users to walk up to a Thunderbolt 2 docking station that includes USB 3.0 ports and use a single Thunderbolt 2 cable to move 4K video from their PC or notebook while also using USB peripherals such as a USB 3.0 storage device, keyboard, mouse and Gigabit Ethernet. Docking stations with this functionality exist for both Thunderbolt 1 and USB 3.0 today. Although USB 3.0 docking stations are more popular and widespread, they only support 2K video due to bandwidth limitations. Both work well in the PC environment, but USB works better in the consumer world.
The instant response time demanded by smartphone and tablet users continues to drive all aspects of the consumer experience with video and data. This demand for faster response time, combined with consumers’ bottomless appetite for storage and higher resolution video, drives the need for faster wired interfaces such as 10G USB and Thunderbolt 2. These standards reduce system latency and enable access speeds to external storage that are comparable to access speeds to internal storage devices. In the next three years, Thunderbolt 2 will grow in the PC market as a proprietary standard, while both the PC and the consumer world will embrace 10G USB for widespread transport, viewing, capture, and streaming of 4K video in the office and home.
As senior product marketing manager for semiconductor USB digital IP at Synopsys, Eric Huang is responsible for managing USB 3.0 and USB 2.0 IP. Huang has worked on USB since 1995, starting with the world’s first BIOS that supported USB keyboards and mice while at Award Software. Huang served as chairman of the USB On-The-Go Working Group for the USB Implementers Forum from 2004-2006. Huang received an M.B.A. from Santa Clara University, an M.S. in engineering from University of California Irvine, and a B.S. in engineering from the University of Minnesota.