The fastest flash card may not be the best choice for your embedded application
September 25, 2015
It still amazes me to see embedded OEM design decisions for flash cards being made based on which card has the fastest interface. The advertising head...
It still amazes me to see embedded OEM design decisions for flash cards being made based on which card has the fastest interface. The advertising headline of “Fastest Card on Market” generally should be followed by the disclaimer, “Good for consumer applications with low duty cycles, unconcerned about BOM control or long life cycles.”
In my opinion, the main objective of any embedded OEM designer should be reliability and meeting the design objectives. Many embedded systems don’t require extremely high data rates, but the “fastest” card on the market somehow conjures up thoughts of “the best card on the market.” This is rarely the case.
To reach high performance and high capacity, flash card designers must make compromises in their design. Since the vast majority of flash cards are used in consumer applications, where speed and performance rule, the compromises are pushed in that direction. Reliability for a consumer camera or other device is far different than for an industrial IoT application.
What I’ve seen is many embedded OEM designs for industrial applications using an off the shelf consumer SD or CF card, which is very fast and/or high capacity, but never intended to run an operating system or be used 24/7 for long periods of time.
Without a serious accelerated life test during the design phase, both consumer and industrial cards may appear similar. But thorough testing and analysis of the application requirements and flash card specs will show deficiencies.
Since Cactus Technologies is an embedded flash storage supplier which focuses on highly reliable, long life cycle flash storage products with locked BOM control, our best customers tend to be OEMs who initially went with a flash card that wasn’t intended for their embedded designs.
Unfortunately for these OEMs, they needed to experience the pain of field failures to realize there was an issue. Understanding overall system objectives and designing with reliability as the primary purpose would have eliminated this painful experience. I encourage embedded designers to review the actual performance requirements of your memory system performance and reliability prior to making the decision on flash storage vendors.
Steve Larrivee is VP Sales & Marketing for Cactus Technologies and has over 30 years’ experience in the data storage market, including 10 years with SanDisk and 5 years at Seagate Technology.