How to Check SSD TRIM and Measure Read/Write Speed in Windows

TRIM and speed testing answer different questions. TRIM tells the SSD which blocks no longer hold live data; a benchmark measures performance under a particular workload. Neither result alone proves that an SSD is healthy.

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 1

Check whether Windows enables delete notifications

Right-click Start and open Terminal (Admin).

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 2

Run:

fsutil behavior query DisableDeleteNotify

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 3

NTFS DisableDeleteNotify = 0: NTFS delete notifications are enabled.
NTFS DisableDeleteNotify = 1: they are disabled.

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 4

The command reports the Windows setting. It does not prove that every controller, RAID layer, virtual disk, or USB adapter passes TRIM to the physical SSD.

If the NTFS setting is disabled and the storage vendor has not instructed otherwise, enable it with:

fsutil behavior set DisableDeleteNotify 0

Review the Windows retrim schedule

Search Start for Defragment and Optimize Drives. Select the SSD to confirm that Windows recognizes its media type, then select Change settings to review the schedule.

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 5

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 6

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 7

Check the TRIM command status of the SSD, and check the read and write speeds. Picture 8

Keep normal scheduled optimization enabled unless the PC manufacturer or storage administrator documents a reason to change it. Windows applies a storage-appropriate action; the word “Optimize” does not mean it blindly performs a traditional HDD defragmentation on every SSD.

Measure SSD read and write speed

Before testing, close large transfers and other storage-heavy applications, connect a laptop to power, and make sure the SSD has reasonable free space. Encryption, cache state, temperature, background activity, power mode, test size, and queue depth can all change the result.

For a quick built-in assessment, open Terminal (Admin), replace C with the intended SSD's drive letter, and run:

winsat disk -drive C

WinSAT reports several storage measurements, including sequential and random results. Record the exact command, Windows power mode, and free space if you plan to compare runs.

For manufacturer comparisons, use the SSD vendor's supported benchmark or a reputable tool with the same test settings each time. Avoid running write-heavy benchmarks repeatedly; they consume write cycles and may trigger thermal throttling.

Interpret benchmark results carefully

Compare like with like: the same interface, test size, queue depth, and amount of free space.
SATA and NVMe drives have different interface limits; a lower number than another model is not automatically a fault.
Short bursts may use a fast write cache, while long transfers can be slower after that cache fills.
A very low result can come from a slow USB enclosure, negotiated link speed, heat, power saving, encryption, background work, or a nearly full drive.

Check health separately

Review the SSD's SMART/health data and firmware with the manufacturer's utility. Back up immediately if Windows logs storage errors, files become corrupt, or the drive disconnects. TipsMake covers drive-health checks and explains why SSD optimization differs from HDD defragmentation.