How to check storage speed after an OS update

Your computer may feel slower after an OS update, or a file transfer may take longer than it used to. That does not automatically mean the update damaged your drive. Background setup tasks, power settings, and different test conditions can all change a speed result.

Use a repeatable check first. TooLab’s Storage Test measures large-file disk speed and small writes in your browser, so you can compare results without installing an app.

Check storage speed

1. Open the Storage Test on the computer and drive you want to check. If you are testing an external drive, connect it directly to the same port you used before, rather than through a different hub.
2. Close file transfers and applications that are busy reading or writing files. Keep the same browser open for each run, and use the computer in the same power state each time.
3. Run the test and note the large-file speed, small-write result, and overall score. If the test presents more than one result, record each rather than comparing only the score.
4. Run it once more after a few minutes. Compare the two runs, then compare them with a result from before the update if you saved one.

A single result is only a snapshot. For a useful comparison, use the same computer, browser, drive, connection, and power source. Avoid running the test while another task is copying, installing, or syncing files.

What the result means

The results are close to your earlier test

The update probably did not cause a clear change in the storage performance measured by this test. A computer can still feel slower because of startup apps, changed settings, or work happening in the background. Check whether the slowdown affects file transfers too, or only one application.

Large-file speed is lower

Large-file speed describes how quickly the drive handles bigger blocks of data. A lower result can happen when the drive is busy, nearly full, hot, or connected through a slower port or adapter. Repeat the test when the computer is idle and check that you are testing the same drive and connection.

Small writes are slower, but large-file speed is similar

Small writes measure a different kind of work, such as saving lots of little changes. This result can vary more when background services are scanning, indexing, or updating files. It does not by itself prove that the drive is failing.

The score changes a lot between runs

Large differences often mean that something else is affecting the test, such as a scan, file sync, or power-saving mode. Close busy applications, wait for the system to settle, and run the test again under consistent conditions. Browser storage benchmarks can vary between runs, as explained in Why storage benchmarks vary between browser runs.

Both results are much lower than before

First rule out a changed test setup. An external drive may be plugged into a slower port, or the computer may be using a power-saving setting. If the same drive is consistently slower in repeated tests and everyday file transfers, continue with the checks below.

How to fix slow results

1. Give the update time to finish. After a major update, the system may still be indexing files, syncing, or completing setup in the background. Leave the computer connected to power and idle for a while, then retest.
2. Restart the computer. A restart can finish pending update tasks and clear a process that is holding the drive busy. After restarting, wait for startup activity to settle before testing.
3. Check what is using the drive. In Windows 11, open Task Manager and look for a process with sustained disk activity. On macOS, open Activity Monitor and check the Disk section. Let legitimate updates, backups, or scans finish instead of ending system processes at random.
4. Use a consistent power mode. On Windows 11, check Settings › System › Power & battery and avoid comparing a power-saving run with a performance-focused run. On a Mac laptop, check System Settings › Battery and note whether Low Power Mode is enabled. Retest using the same mode you used before the update.
5. Check available space. On Windows 11, open Settings › System › Storage. On macOS, open System Settings › General › Storage. If the drive is almost full, remove files you no longer need or move large files to another drive, then retest.
6. Check for a connection or driver change. For an external drive, try the same direct port and cable used in your earlier test. If the slowdown began immediately after the update and persists, check your computer maker’s support guidance for storage or chipset updates. Avoid installing a driver from an unknown source.

When the drive may need service

A low browser test score cannot confirm that a drive is damaged. Look for other signs: repeated file errors, files that will not open, unusually long freezes during ordinary copying, or a drive that disconnects. Back up important files before trying repairs or more intensive tests. If the same problems continue on another port or computer, use the manufacturer’s diagnostic guidance or contact a repair shop. For an external drive under warranty, ask the manufacturer about replacement before opening it.

What this test can and cannot tell you

The Storage Test measures performance through a browser, including large-file speed and small writes. It is useful for comparing the same setup before and after a change, but it is not a complete drive-health check and does not reproduce every kind of file copy or application workload. Browser storage permissions and browser behavior can also affect a test; see What browser storage permissions mean for a disk test.

Save the result, the date, and the conditions you tested under. That gives you a fair baseline if you need to compare again after another update or a repair.