Write Activity and the Cluster Map

The Write activity page visualizes writes Windows reports for the selected drive. It helps you see which processes write data and where those writes land.

Understand the map

Legend item	Meaning
Allocated	Space occupied on the drive.
Free	Space available on the drive.
Written just now	Blocks affected by recent writes.
Written earlier	Blocks written during the observation period.
Active writes of the selected process	Recent writes associated with the selected process.

One visible map block represents multiple file-system clusters. The map subtitle tells you the grouping and corresponding size. A highlighted square is therefore not necessarily a single file or one hardware flash page.

Counters

The summary shows data written since the current observation started, write operations, average write size and a recent write-rate history. These describe writes reported by Windows for the selected drive. They are not lifetime SMART totals or direct measurements of SSD wear.

Pause and reset

Pause stops applying new writes to the display, freezing the map and counters. Resume continues observation; the paused interval is not added back as a historical recording. Reset clears counters, process and file lists and written-block marks for a fresh session.

The page focuses on writes. Use the benchmark page when you want to compare read performance.