-
-
NAVIGATION
- Home Page
- Shop by Brand
- Shop by Product
- New Arrivals
- Promotions
- Blog
-
-
-
HELP & SUPPORT
- Help Desk
- Contact Us
- Technical Support
- Returns / RMA Request
-
Confused when you see two capacities in the name of a solid state drive? In most cases, the larger number represents the total flash capacity of the drive and the smaller number is the usable storage space on the drive. The reason for this is often because the drive you're looking at has been over-provisioned by the manufacturer.
What is Over Provisioning?
Over Provisioning (OP) is when a certain percentage of an SSD's free space has been allocated to help maximize the lifetime, endurance, and overall performance of the drive itself. It does so by providing a permanent "swap space" for the drive's controller to manage all the data traffic and storage for the drive. By guaranteeing this free space for the controller to move data more efficiently, the SSD no longer has to waste time preparing space on demand for writing, overwriting, and accomplishing basic NAND maintenance tasks like Garbage Collection, Wear-Leveling, and Bad Block Management as the drive fills with data under sustained workloads.
While some users may still see over provisioning as a costly waste of storage capacity, it actually offers significant benefits in smaller capacity drives and drives with heavy application usage. For example, a 64GB SSD at 7% OP would only be left with 60GB of storage space for the user (more examples seen in the chart below) but no longer runs the risk of the drive filling completely, allowing behind the scenes processes to continue running smoothly without interruptions in performance to get the most from the drive during its life span.
Detailed Benefits of Over Provisioning
Comparing Full Capacity and Over Provisioned Capacity
This chart illustrates the difference between the amount of flash on the drive and the available storage capacity after over provisioning.
Total Capacity | OP'd Capacity (7%) |
64GB | 60GB |
128GB | 120GB |
256GB | 240GB |
512GB | 480GB |
1TB | 960GB |
2TB | 1920GB |
For More on Over Provisioning
We suggest reading the following in-depth articles on the subject:
Exploring the Relationship Between Spare Area and Performance Consistency in Modern SSDs
AnandTech.com