How to see which app is hammering your disk
Sort the Disk read or Disk write column on Pulse by Zaweba's Live page to rank every app by how hard it is working your drive, from Windows' own counters.
Disk reading and writing are shown for every app in Pulse by Zaweba, in two columns on its Live page. Click Disk read or Disk write to sort it biggest first, and the app hammering the drive comes to the top. The Disk graph across the top shows the whole PC's read and write throughput in two colours.
A busy drive makes the whole PC feel sluggish: windows open slowly, files take ages to save, and the drive light barely goes out. Finding the program responsible is the first step to fixing it.
Where the numbers come from
Pulse takes each app's disk figures from Windows' own per-process I/O counters. That means file reads and writes are counted even when Windows serves them from its cache rather than the physical drive. It is a fair picture of how much work each app is asking for, which is what you want when hunting a heavy user.
Every process of one program is gathered into a single row, with the program's icon and its friendly name. Backup tools, browsers and game launchers often run several processes at once, and Pulse adds them together so you see the program's real total.
Finding the heavy user
Open Pulse and go to the Live page (Ctrl+1). Look at the Disk graph first to see whether the drive is busy at all, and whether it's mostly reading or writing. Then click the matching column heading: Disk read for reading, Disk write for writing. The table updates every second without losing its sort order, so you can watch the top rows settle.
Common culprits include indexing and search, antivirus scans, cloud sync clients copying files, updates unpacking, and browsers writing their caches. A game launcher patching a game can write a great deal for a long time.
When it isn't happening now
Disk storms tend to come and go. Pulse keeps a minute-by-minute record for 30 days by default, including each busy app's disk bytes. The History page (Ctrl+3) shows today, yesterday or this week; the graphs help you see when the PC was busy, and the Top CPU users list often points at the same program, since heavy disk work usually comes with processor work too.
Doing something about it
Once you know the program, decide whether its work is reasonable. A backup or an update will finish on its own. A sync client copying a huge folder may need pausing in its own settings. A program that never stops writing may have a fault.
Pulse lets you act from the same table. Select the row and choose Open file location to see where it's installed if you don't recognise it. End task closes every process of the app after a red confirmation; use that for something stuck, and save your work first if it's something you use.
Keeping an eye on the drive itself
Constant heavy writing wears an SSD over time. Pulse's Temperatures page has a Drive health group showing, for NVMe drives, the percentage of rated life used, available spare and media errors, and the drive health alert warns you if those decline. Pulse by Zaweba does all of this as a normal user, with nothing sent off your PC.
