By Kalvin Subbadu, Sales Manager Components, WD South Africa

When it comes to surveillance systems today, the Digital Video Recorder (DVR) is the heart of any solution. However, while many people understand the importance of the DVR, they fail to give thought to what goes inside it – specifically, the hard drive that is absolutely essential for the recording, playback and storage of surveillance footage. Using just any hard drive in a DVR can cause catastrophic consequences, and is often the single point of failure in security systems, bringing the entire system crashing down. Should hard drive data become corrupted, or the drive should fail, everything recorded on that drive will be lost, negating the very purpose of surveillance. Dedicated, purpose-built surveillance drives have been designed with the specific demands of this environment in mind, ensuring they are more reliable and longer-lasting than other hard drive technologies.

When it comes to DVR hard drives, cheapest is certainly not best, especially when given the critical nature of security solutions. However, purpose-built surveillance drives do not carry a significantly higher price tag than desktop drives, so risk of premature failure carried by desktop drives far outweighs any additional cost involved.

In addition, increasingly popular 720p high definition (HD) cameras impose a massive extra workload on hard drives, requiring three to four times the amount of storage and processing power of standard VGA cameras. With regular desktop hard drives in place under this type of strain, the drives will inevitably fail even sooner, creating serious issues for surveillance systems. The next evolution to 1080p cameras will only exacerbate this challenge, further doubling network traffic and placing hard drives under strain.

When a hard drive is designed and engineered, specific attention is paid to the role the drive is made to play. For example, a laptop drive uses a 2.5-inch form factor and is typically designed with shock resistance in mind, as well as lower power consumption to extend the battery life of a notebook. This in return limits capacity and performance. Enterprise and server-class drives are optimised for 24/7 operation and high performance, but utilise higher power draw and are noisier and run hotter than other drives. Conventional desktop drives are designed for a typical eight to five office environment, with a 3.5-inch form factor and capacity of up to 6TB. None of these drives are optimised to the demand of a DVR environment, which requires high capacity, high performance, the ability to operate 24/7 as well as cool, quiet operation that minimises vibration.

Purpose-built security and surveillance drives can deal with up to 32 simultaneous HD camera streams, and can effectively deal with the unpredictable workloads of surveillance environments, which are dependent on activity in the area being monitored. Using the entire cache and proprietary drive firmware such as AllFrame, found in WD Purple surveillance-class hard drives, the workload is monitored to identify the number of incoming streams and the amount of bandwidth required by each. AllFrame works to reduce frame loss, improve playback and increase the number of drive bays supported, reducing video interruptions that commonly occur when desktop hard drives are incorrectly used as storage in security systems.

Since the ability to deal with a variable workload typically means that the drive heads have to jump around, which can increase noise and vibration, WD Purple drives feature exclusive IntelliSeek technology. IntelliSeek ensures the WD Purple is able to calculate optimum seek speeds, reducing power consumption, noise and vibration that can damage hard drives and cause them to wear out more quickly. Surveillance drives are also designed to handle multiple data streams where they will be writing more than reading, and feature low power draw, resulting in less radiated heat, which prolongs the life of hardware. In addition, WD Purple drives are built for compatibility with industry-leading chassis and chip set manufacturers for seamless integration into new or existing video surveillance system.

The technology behind surveillance drives is engineered and optimised to function effectively in the demanding, high temperature, always-on, surveillance security systems. This ensures reliability and quality video play back, extended operation, and essential support for critical security applications.