3 Types of SSD over-provisioning and how it works?

Geekom Official

Staff member
Aug 25, 2022

What is SSD over-provisioning?​

Over-provisioning, in a storage context, is the inclusion of extra storage capacity in a solid-state drive. SSD over-provisioning can increase the endurance of a solid-state drive by distributing the total number of writes and erases across a larger population of NAND flash memory blocks and pages over time.

Types of over-provisioning​

There are three types of SSD over-provisioning:

Inherent. According to Seagate, every SSD has at least some over-provisioned capacity that is used for the following:
  1. The controller's firmware
  2. Failed block replacements
  3. Vendor-specific features
Learn more: Here ✅
This capacity is inherent in the difference between the binary and decimal notation used to measure data amounts and capacities of SSDs.
Adequate over-provisioned capacity is essential to an SSD's long-term performance and reliability. Only the SSD controller can access this capacity.


An SSD manufacturer might also set aside additional capacity to accommodate write-intensive workloads. The added capacity is anywhere from 7% to 28% -- and, sometimes, even more -- in addition to the inherent over-provisioning. This added capacity is also not available to the host.


In some cases, a user might over-provision a drive even further using the capacity that's available to the user. They would use a vendor-provided tool or create a separate partition that prevents the defined space from being used to do this. This is not the same as the inherent or vendor-configured over-provisioning, where the reserved capacity is available only to the storage controller and is not visible to the user or the host system. Only the remaining, unreserved capacity is available to the host. The user-configured over-provisioning comes out of the unreserved user capacity.

More information: Here ✅


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