Embedded system designers need more from a storage system than higher capacities. Today's applications require enhanced performance, reliability, and security, all of which can effectively be met with advanced solid-state storage. This technology offers many tangible benefits, including multiyear product cycles, no product wearout, the ability to accurately forecast usable storage system life, and security options beyond encryption. But OEMs continue to design in substandard storage based on five prevalent myths.
Myth 1: It's too expensive
Not necessarily. The megabyte capacity of traditional storage products far exceeds user requirements in many applications. Yet to maintain average selling prices, hard-drive manufacturers offer increasingly higher-capacity hard drives, forcing users to buy 40 Gbytes or more of storage when their application requirements may be for as little as a few gigabytes.
A recent study concluded that most enterprise system OEM applications require less than 4 Gbytes. An edge router is a typical application that stores both an operating system and data log files using less than 4 Gbytes. Since there is cost parity between hard drives and solid-state at this capacity, solid-state storage is no longer too expensive.
Advances in the last 15 years have made solid-state storage more affordable today than ever. Working with a typical $250 storage budget, companies can purchase the same capacity in either solid-state or hard drive. For the same cost as a hard drive, they can gain the additional benefits that come with solid- state. So, the cost per useable gigabyte now favors solidstate storage over hard drives in many applications.
Myth 2: Superior hard-drive performance
Field failure rates for hard drives are up to 15 times greater than datasheet specifications, according to a Carnegie Mellon University report dated February 2007. And according to a February 2007 Google study, once a hard drive has its first scan error, whether it be for reallocation, offline reallocation, or probational counts, it is 39 times more likely to fail within 60 days.
When hard drives are used in more demanding applications that extend duty cycles or in applications with vibration, temperature variation, or other environmental challenges, field failure rates are much higher.
Hard drives will always be better in applications requiring massive amounts of storage capacity, since solid-state is a long way away from offering a cost-effective terabyte of storage. But for many applications, solid-state storage offers better durability and a significantly lower total cost of ownership.
Myth 3: Costly product requalifications
Not so. Many flash card and hard-drive manufacturers force requalifications on their customers due to product development techniques they employ to minimize their bill of materials costs. Conversely, developers of advanced solid-state storage technology leverage product development strategies that enable them to continually introduce technology advances without triggering product requalifications for users.
Myth 4: Unavoidable wearout
Not with solidstate technology. Storage systems should not wear out or fail during the required deployment cycle, as the costs associated with unscheduled downtime, field maintenance, product recalls, lost revenue, and customer goodwill are significant.
Solid-state storage technology features patented technologies such as robust wear-leveling and error correction code (ECC) algorithms, as well as early warning systems that forecast useable life to virtually eliminate the chances of storage system wearout. The endurance of a traditional flash card simply cannot match that of an advanced storage technology that offers wear-leveling over the entire drive and 6-bit ECC.
Myth 5: Limited security options
In the past, embedded system design challenges due to the small footprint and low-power requirements for storage systems prevented storage security options beyond basic encryption technology. Leading manufacturers of advanced solid-state storage technology offer an array of advanced user-selectable security options that prevent IP theft, protect application data, and manage data security via the host system, not the storage product.
Total cost of ownership
Many designers assume that low-cost storage solutions will lower their total cost of storage ownership, but a wide array of factors must be considered. It is far more complex than simply calculating the cost differential between various storage products. A lower individual unit cost per storage product is only relevant if all products being compared deliver the same benefits to the user.