SSD optimization and TRIM
O&O Defrag provides file optimization and SSD TRIM maintenance. TRIM tells an SSD which storage regions Windows no longer needs. It does not sort files or serve as a secure-erasure command.
File layout and internal SSD maintenance
Windows describes files in logical clusters and contiguous regions (extents). The SSD controller maps logical addresses to physical flash memory. Joining a file’s extents does not guarantee that its data occupies one physical flash block. ClusterView consequently shows the volume layout, not a direct map of NAND cells.
Windows / logical volume
- File optimization: Joins file extents in the file system. Moving data causes writes.
- TRIM: Reports logical regions no longer in use. It does not join file fragments.
SSD controller / physical flash
Garbage collection can copy still-valid pages elsewhere before erasing a flash block for reuse. TRIM helps the controller identify data it no longer needs to preserve. The controller determines the timing and physical placement; a file’s fragment count does not directly reveal how many erase cycles will occur.
These operations complement each other; they are not a prescribed sequence of steps.
Why optimization causes writes
Moving file data requires writes, so an SSD’s reported write counter can increase during file optimization. The aim is to reduce worthwhile file-system fragmentation while limiting the data rewritten. Keep the ROI protection enabled and use the Advisor’s recommendation instead of optimizing repeatedly just to reach zero fragmentation.
Host writes and internal flash writes are different measurements: garbage collection can cause additional internal writes, often called write amplification. Check which counter the device reports. There is no fixed conversion from fragments removed to write cycles saved or additional SSD lifetime.
Three separate settings
| Setting | What it controls |
|---|---|
| Windows delete notifications (TRIM) | Whether Windows passes deletion information to supported SSDs. |
| O&O Defrag scheduled TRIM | How often Defrag performs its SSD maintenance action. |
| Windows scheduled drive optimization | Whether Windows also runs its own scheduled optimization task. |
A disabled Windows optimization schedule does not prove that delete notifications are disabled. Likewise, enabling Windows TRIM does not create a Defrag schedule.
Configure SSD maintenance
- Open Automatic optimization.
- Review Optimize SSDs regularly.
- Select the Execute TRIM interval.
- Review Pass on delete notifications to SSDs (TRIM).
- If Windows reports notifications as disabled, enable the setting if appropriate.
- Check the resulting status after the change.
Changes to this page are applied as you make them. If Windows rejects a change, the control returns to the reported state and displays a message. An unknown TRIM state means the application could not read it, not that it is off.
The page offers intervals from every 6 hours to every 2 weeks. Use the normal product defaults as a starting point and adjust to your maintenance requirements.
Avoid overlapping schedules
If the dashboard reports that Windows and Defrag both optimize drives on a schedule, review which should own regular maintenance. The dashboard's Leave it to O&O Defrag action asks to turn off the Windows schedule. You can restore that schedule in Windows later.
SSD file optimization
When an SSD has meaningful file fragmentation, the Advisor can recommend SOLID. Keep the ROI protection enabled unless you have a specific reason to change it. Do not use a traditional sorting method only to remove the last small amount of reported fragmentation.
If the device is misidentified, see Drive detection. OODCMD does not expose an SSD TRIM command.