read-intensive SSD (read-intensive solid-state drive)-a tech explanation

Tekmart Data Center Team/ April 24, 2021/ Data Centre Hardware Equipment Technical Resources, Datacenter Infrastructure News, Expert Advise and Opinion, Industry News and Expert Advice, Read-intensive SSD (read-intensive solid-state drive), SAS SSD (Serial-Attached SCSI solid-state drive), Solid-state storage

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A read-intensive solid-state drive (SSD) is a storage or caching device intended for use with applications that write data infrequently.

By Carol Sliwa

A read-intensive SSD is able to use NAND flash memory with a lower endurance level than an SSD that targets write-intensive workloads, such as online transaction processing, high-performance computing, and data warehousing.

High numbers of writes can cause NAND flash wear-out, and manufacturers of SSDs intended for write-intensive workloads generally use more reliable types of NAND, overprovision the flash and/or use special algorithms to improve endurance. 

Drive manufacturers sometimes offer SSDs of varying endurance levels and capacities earmarked for read-intensive, write-intensive or mixed workloads. For example, a read-intensive SSD might guarantee only one to three drive writes per day (DWPD) but offer higher capacity than a write-intensive SSD that supports up to 25 DWPD.

The write-intensive SSD’s usable capacity may be lower because a greater percentage of NAND flash is reserved to handle garbage collection and compensate for potential chip wear-out or failure.

Read-intensive SSDs tend to use the least expensive types of NAND flash memory, such as multilevel cell (MLC) and triple-level cell (TLC) flash. Write-intensive SSDs more commonly use enterprise MLC (eMLC) or single-level cell (SLC) flash, which offer higher endurance than MLC and TLC. Storage systems that use less expensive MLC for write-intensive workloads generally employ special algorithms and other techniques to manage endurance.