There are many differences between Industrial and Commercial Grade flash storage devices. In many cases Commercial Grade products initially appear to meet the needs of a specific application. But, the true test of a product is its ability to last the lifetime of the application in the field. In this section we explore the considerations which should be taken to determine the right product for your application.
Industrial Grade uses SLC (Single Level Cell) NAND versus Commercial Grade MLC (Multi Level Cell) as the storage medium for data. SLC NAND has 20-30 times more endurance cycles than MLC NAND and has significantly better data retention life and functionality at extreme temperatures.
While the raw NAND memory used in a flash storage device limits its capabilities, the intelligence of any flash card is determined by the controller and firmware design. Industrial Grade controllers are designed from the ground up with data integrity and reliability as their primary characteristic. Commercial Grade controllers are generally designed to focus on cost and lifting the level of MLC NAND reliability to an acceptable level for some applications.
Industrial Grade products have sophisticated Wear Leveling, Defect Management and Error Checking & Correction (ECC), along with many trade secret techniques developed to deliver reliability across a wide range of applications and environments. Commercial Grade firmware, with its shorter life cycles, is developed to with time to market and cost as its primary goals.
Write Endurance is a calculated number which represents how many time a logical block of NAND memory can be written prior to failure. This figure takes into account all wear leveling, defect management techniques and Error Checking & Correction (ECC). Industrial Grade products are rated at > 2,000,000 endurance cycles per block, while Commercial Grade products are in the 50,000 – 100,000 range.
The Commercial Grade offerings are significantly lower priced than the Industrial Grade products. In many cases they are several times less expensive than an equal capacity Industrial Grade offering. This is the main reason OEMs consider use of the lesser reliability MLC NAND devices.
Industrial Grade products have off the shelf extended temperature ratings of -45C to 90C. In addition, they can be screen tested to much higher and lower temperatures. Commercial Grade products are typically rated at only 0C to 70C or in many cases not rated. We have been able to screen test some Commercial Grade devices to wider temp ranges, but Industrial Grade is by far more reliable at temperature.
Cactus Industrial Grade products have a locked BOM. A locked BOM signifies there will be no changes to the controller, firmware or NAND without the issuance of a Product Change Notification and many months for approval of the change by the OEM. The Cactus Commercial Grade products also have BOM control, but shorter life cycles and transitions than Industrial Grade.
Cactus notifies the OEM of all changes of BOM for the Industrial Grade product offering. Samples and 6+ months are given to qualify these changes. For Cactus Commercial Grade products, the OEM is notified of change, but transition can be as short as 1-2 months. This is due to the rapidly changing nature of MLC NAND components.
Industrial Grade products exist for >10 years in many cases with as few as 2 Product Change Notifications during that time. The Commercial Grade products typically have lives of 12-18 months.
Cactus Industrial Grade products are designed with several techniques and circuitry used to minimize the effects of unexpected power loss. Commercial Grade products have some resistance to unexpected power loss, but it is not near as robust as Industrial Grade devices.
Cactus Industrial Grade MTBF is rated at > 4,000,000 hours versus most Cactus Commercial Grade products at 200K.