Which app is hammering your drive? Pulse by Zaweba shows you

A drive light that never goes out, or a PC that feels sticky every time you open a folder, usually has one cause: some program is reading or writing far more than you'd expect. In Pulse by Zaweba every app row in the Live table has two columns for this, Disk read and Disk write, so you can see which program is responsible rather than guessing.

How Pulse counts disk use

The figures come from Windows' own per-process I/O counters. That has a useful consequence. File reads and writes count even when Windows serves them from its cache rather than touching the drive itself. So an app that keeps rereading the same files will still show up, even though the drive might not be doing much physical work for it.

Think of the columns as how much file work this app is asking for. That is usually what you want to know when hunting for a misbehaving program, because the app asking is the app to deal with.

For the whole PC, the Disk graph at the top of the Live page shows reading and writing as two lines in two colours. It scales itself to whatever is happening and shows the rate, so you can tell a gentle trickle from a big copy.

Finding the culprit

Open the Live page and click the Disk write heading. The busiest writer goes to the top, because number columns sort biggest first on the first click. Then try Disk read. Often the two point at different programs: a backup tool reading everything, say, and a browser or an updater writing.

Since every process of one program is gathered into a single row, a program that spreads its work across many processes still shows as one honest total. The table updates in place every second, so your sort order and selection stay put while the numbers change.

If you only care about one program, type part of its name into the Find box to filter the table down to it, and watch its two columns on their own.

What the patterns usually mean

Heavy writing that never stops often comes from something saving, syncing or logging. Heavy reading for a few minutes after start-up is common, as apps load their files. Antivirus scans and backup tools tend to read a lot and write little. Downloads write steadily at roughly the rate of the network.

None of these are automatically a problem. What matters is whether the activity makes sense to you. A photo app writing while it imports pictures is doing its job. An app you haven't opened all week writing constantly is worth a closer look.

Acting on it

Select the app and use Open file location to see which folder its exe lives in. That alone often answers the question of what the thing is. If you're sure you want it to stop, End task closes every process of that app after a red confirmation. Be careful with this while a program is writing, since stopping it mid-save can leave a file half written.

Looking back

Disk activity often happens while you're away. The History page records each busy app's disk bytes minute by minute, so you can come back later and see when the drive was busy. Pulse keeps 30 days by default, and you can change that in Settings, History.

If a drive is very busy for a long time, it's also worth a glance at the Drive health group on the Temperatures page. Heavy use isn't harmful in itself, but a drive that is wearing out deserves to be noticed early, and Pulse can alert you when its health declines.