In the digital content market, it's all about high speed and high capacity, and SAS (and SAS/SATA) storage systems fit the bill.
By Thomas M. Coughlin
With media and entertainment content increasing in resolution, content data files have swelled, and data throughput has increased proportionally. At the same time, content producers are under more pressure than ever before to control prices. SAS-based storage systems play an important role in making these seemingly contrary goals possible.
The introduction of digital production technology is a great enabler of professional creativity. It encourages new levels of realism and special effects in the content and increases the efficiency of production at the same time as it decreases the costs of production. Because of the ease of digital capture of video content, producers now shoot a lot more hours before editing. This results in many more hours of content than was the case for film capture, similar to the trend seen with the conversion from film to digital still photography.
Generally, digital content producers shoot 10x more hours of content than was typical with film production. Digital production has resulted in more content, and increasingly more content is kept on associated post-production storage systems. Furthermore, this digital content is kept online for a longer period of time. Some facilities even use disk arrays for “active archives.”
As the resolution of video content increases, the digital storage required increases. Table 1 shows the bandwidth and one-hour storage capacity demands of typical professional media formats (including sound) and the primary applications in which they are used. Higher bandwidth results in greater production of storage content, and thus more demand for storage capacity.
Feature film resolutions are on an upward roll, particularly for the very high end of the market. For example, 2K resolution films are common and 4K resolution films are becoming more common. Table 2 shows some metrics for feature films, assuming a 10-bit deep file.
Because storage system backplanes can be built to support both SAS as well as SATA drives, storage system integrators have more freedom in designing tiered-storage environments. SAS and SATA support makes it easy to create cost-effective, multi-tiered storage solutions in a single cabinet, using low-cost SATA drives for secondary storage while staging critical primary data on higher-performance SAS disks.
Creating the potential for multi-tiered storage within one enclosure can be important, particularly for smaller studios, since they may not use high-speed storage networks. As such, workstations at these facilities benefit from having multiple storage options in direct-attached devices.
Because of the time-critical nature of the media/entertainment markets, storage systems are often over-provisioned to ensure there will be no dropped data streams. With video work, a dropped stream can cause significant delays in an expensive facility.
SAS-based storage systems deliver high performance, often with external Fibre Channel interfaces. Some of these arrays cost as little as $1.31 per gigabyte and provide storage capacities of 10.5TB or more per rack and data throughput rates of 380MBps sustained (enough to service 10 standard definition, or SD, resolution streams). And many of these storage systems allow a choice of SAS or SATA drives on a common backplane.
Many direct-attached storage (DAS) SAS systems offer dual-controller active-active support, as well as built-in performance analysis and management features, including drive rebuild functionality. These disk arrays can mix SATA and SAS to create an internal tiered storage architecture. Storage systems with capacities of tens of terabytes or more are currently on the market, but with 1TB SATA drives ramping up, capacities will swell this year.
SAS systems can also offer extremely fast data rates, such as those required in a multi-stream studio environment. For instance, using a dual 4X SAS host connection with dual controllers, some disk arrays can provide 12GBps throughput. Other, lower-cost disk subsystems use full-duplex SAS operation to provide 1.5GBps to 2GBps data-transfer rates. And many SAS RAID controllers support multiple streams of high-definition, or HD, video with parity RAID protection.
SAS and SAS/SATA storage systems are key enablers for the digital video production industry. SAS enables reliable arrays that support fast data rates and multi-stream video editing systems in both networked storage and direct-attached storage environments.
By being able to share resources with lower-cost, high-capacity SATA disks, users and systems-storage integrators can create multi-tier storage environments—even in the most cost-sensitive facilities. And a tiered-storage architecture enables active working archives. These elements combine to make SAS a vital component in editing and production facilities.
Tom Coughlin is president of Coughlin Associates and chairman of the annual Storage Visions conference. Coughlin Associates provides storage market and technology analysis services. For more information, go to www.tomcoughlin.com.