Industrial Grade vs. Consumer Grade Flash Devices
We often get asked what is the difference between consumer and industrial flash devices and why industrial grade is so much more expensive? Surely it all does the same thing? This Tech Talk article explores the key differences between the two, covering price, capacity, performance and much more. They initially appear to meet the needs of a specific application and it is easy to see why.
On the surface, they look the same. Identical mechanical design, same capacity and matching form factors. However, there are significant differences between industrial and consumer-grade flash devices and it’s important to consider the impacts these differences have on reliability, endurance, compliance and total cost of ownership before selecting a device that is fit for purpose.
But what is the real difference between the two? Let’s take a look…….
One of the main differences is the type of NAND Flash used and there are many different types of NAND available. Consumer NAND is typically 3D TLC which is cheap, has decent performance and will do just fine in storing data such as photos, video, music, apps etc. 3D TLC NAND is the most common NAND globally available.
Lesser-known Flash such as SLC, MLC and pSLC are strong in the industrial sector. By industrial we mean; aerospace, defence, automation, medical, telecommunications, marine, offshore, IoT and edge devices
NAND Flash Options and Write Endurance
Industrial grade devices outperform consumer devices significantly when it comes to endurance. They use higher grade NAND Technology which can offer up to 200 times better endurance. To put this into context a typical 32GB consumer USB drive will have around 300 programme erase cycles – so all data can be erased and uploaded 300 times. The same for an SLC device will have 60,000+ cycles. SLC NAND has the highest endurance, but at a price, it's incredibly expensive. MLC, pSLC and industrial 3D TLC offer better endurance than consumer-grade but nowhere near as high as SLC. These NAND types offer a balance between price, capacity and performance.
Industrial grade products are tested for extended periods in operation at wide temperature ratings of -45°C to +85°C. Some manufacturers also have the ability to increase the rating through screening or conformal coating options. Consumer grade products are rated at only 0°C to +70°C.
Controlled BOM (Build of Materials)
Industrial grade products have a controlled BOM which specifies there will be no changes to the firmware, NAND, controller or customisation undertaken without the notice of a product change notification (PCN). Consumer products do not adhere to the same control and several changes are made during the products' short lifetime.
Consumer grade components have typical purchase availability of 6-12 months before being replaced or superseded. Industrial grade products using SLC, for example, could exist for more than ten years with one or two Product Change Notifications during that time.
Typical product life cycles are outlined below.
|Consumer 3D TLC
|3 years +
|Industrial 3D TLC
Due to the rapidly changing nature of NAND components and the sheer volume of units being sold when a product using Consumer Grade becomes end of life, usually, it is there one day and gone the next. Industrial products come with a 3 or 6 months product change notification and last-time buy option for all items bought or sampled. This time period of 3-6 months enables the end user to source and test a replacement to ensure a seamless transition.
Flash Device Intelligence
The type of NAND memory selected on its own is not enough to determine data integrity and reliability levels. Whilst NAND defines the endurance capabilities, in order to function must rely on the ‘brains’ which is determined by the controller and firmware design. The advantage of industrial controllers and firmware versus consumer is they have been designed specifically to address the high endurance demands of industrial computing applications. Developed from the ground up the emphasis is placed on core characteristics of reliability and data integrity. In comparison consumer-grade controllers need to appeal to a mass market, this means typically they are a ‘one size fits all’ solution that has been developed with a primary focus on cost and meeting the minimum specifications required to be acceptable. For a project that requires a controlled BOM swapping out one for another simply won’t do as this could have a profound and critical effect on the performance of the application.
In order to increase reliability, there are a host of intelligent firmware techniques available in the market for both industrial and consumer flash storage devices. The most commonly known are Wear Levelling, Error Checking & Correction (ECC) & Defect Management. Similar to NAND, there are different levels of each and industrial device manufacturers ensure they are using the highest available level and invest heavily into the R&D of bespoke firmware to further improve them. The objective is to provide firmware that improves reliability and offers long-term availability without the need to change. Consumer grade manufacturers do not place such importance on long-term availability as the products have much shorter life cycles. Because of the competitiveness of this market, there are immense pressures on cost, performance and time to market. For these reasons often the lower-level options are selected as they are fit for purpose within consumer-grade applications.
Cost & Capacity
One of the main drivers for using consumer NAND technology in industrial applications is cost. The price per gigabyte (GB) is considerably less when compared at base cost against Industrial. However, this does not tell the whole story. In the event of the flash disk becoming corrupt before the life of the application is complete, often the total cost of ownership (TCO) is higher. Just taking into consideration downtime, engineering resources (testing and support), reputation, damage, loss of data and the cost of replacing the wrong devices, you begin to understand why.
Because of how long industrial applications must remain operational for and be supported in the field, the minimum capacities are still available from industrial-grade manufacturers such as Innodisk, and ATP. Consumer grade manufacturers move upwards much quicker as they require the 'sweet spot' where a capacity provides the best yield based on $/GB.
Some consumer-grade products offer low-level software-based resistance to minimise data corruption caused by the effects of sudden power loss. Industrial grade devices offer both software and hardware-based solutions that are more robust. The image below, right, is of a 2.5" SSD with power protection capacitors (the yellow blocks at the bottom) so if a sudden loss of power occurs the capacitors store enough power for the SSD to shut down safely and securely ensuring that all data is retained.