Disclosure: we make SofaDeck, which is one of the options below. Facts about Windows, macOS and other products were checked on 23 October 2026 and can change.
Short answer: press Win+R, type perfmon and press Enter. Performance Monitor is built into every edition of Windows 10 and 11. It graphs any counter you choose — CPU, memory, disk, network, GPU — and can record them for hours so you can catch a slowdown that only happens sometimes. For a quick look, Task Manager is faster; for a glance while a game is full screen, a second screen or your phone is easier. This guide covers all of them.
Which Windows tool to use
| Tool | Open it with | Best for |
|---|---|---|
| Task Manager | Ctrl+Shift+Esc → Performance | A quick live look, ending a stuck program |
| Resource Monitor | perfmon /res | Which process is using the disk, network or memory right now |
| Performance Monitor | perfmon | Graphs of any counter, and logs over hours or days |
| System diagnostics report | perfmon /report | A 60-second health report with warnings explained |
| Reliability Monitor | perfmon /rel | A timeline of crashes, failed updates and app errors |
| Game Bar performance widget | Win+G → Performance | An overlay on top of a game |
| Phone stat tiles (SofaDeck) | Your phone's browser | Watching the PC without covering the screen |
How to use Performance Monitor, step by step
- Press Win+R, type perfmon and press Enter.
- Click Monitoring Tools → Performance Monitor in the left pane.
- Click the green + button, pick a counter (for example Memory → Available MBytes) and click Add, then OK.
- To record over time, open Data Collector Sets → User Defined, right-click → New → Data Collector Set, choose your counters and start it.
- Open Reports → User Defined to read the log when the problem has happened.
By default the graph shows only % Processor Time. The counters that answer most "why is my PC slow?" questions are:
| Counter (object → counter) | What it tells you | Worry when |
|---|---|---|
| Processor → % Processor Time (_Total) | Overall CPU load | It sits near 100% for minutes |
| Memory → Available MBytes | Free memory left | It drops below a few hundred MB |
| Memory → Pages/sec | How hard Windows is paging to disk | It stays high while things stutter |
| PhysicalDisk → % Idle Time | How busy each drive is | It stays near 0% (the drive is saturated) |
| PhysicalDisk → Avg. Disk sec/Transfer | How long each read or write takes | It is regularly above about 0.02 s on an SSD |
| Network Interface → Bytes Total/sec | Traffic on each adapter | It is high when you aren't downloading anything |
| GPU Engine → Utilization Percentage | Graphics load per engine | The 3D engine is pegged with low frame rates |
Rules of thumb, not hard limits: compare against the same PC when it feels fine. Counter names checked 23 October 2026.
Log a problem that comes and goes
Live graphs only help if you're watching at the right moment. A Data Collector Set records counters in the background: in Performance Monitor, expand Data Collector Sets, right-click User Defined → New → Data Collector Set, choose Create manually, tick Performance counter, add the counters above with a sample interval of 5–15 seconds, and start it. When the stutter happens, note the time, stop the set, and open its log under Reports. Look for the counter that changed at that moment. Delete old logs afterwards; long runs at short intervals can grow large.
Watch performance without covering your game
Performance Monitor and Task Manager are windows on the same screen as your game or film. Two lighter options: the Game Bar performance widget (Win+G, then pin it) draws a small overlay, and Task Manager's Always on top option keeps its compact view visible. If you'd rather keep the screen clean, put the numbers on your phone.
SofaDeck turns your phone into a button deck for your PC. From version 1.0.9 its free PC stat tiles show CPU %, RAM %, GPU %, GPU temperature (NVIDIA cards), disk %, network down/up and battery as live buttons with a fill bar, refreshed about every 1.5 seconds. A tile gets a red edge past 90% (83 °C for the GPU, 15% for battery). Tap a tile for the full PC stats sheet. Tiles only update while the page is on your phone's screen, so a phone sitting in a stand doesn't load the PC.
- Install SofaDeck on the PC (free, from the Microsoft Store or this site) and pair your phone by scanning the QR code.
- Open the deck editor, add a button and choose the type PC stat tile, then pick CPU, RAM, GPU or another stat.
- Put the tiles next to the buttons you already use, such as volume, Discord mute or a screenshot key.
Direct installer .exe · 3.7 MB Store version signed by Microsoft No account Local network only Signed updates SofaDeck installs on your Windows PC. Your phone is the remote — it works in the phone’s browser.One email from support@dixonappstudio.com. No list unless you tick the box. PrivacyOr on your PC, go to sofadeck.com/getMore on temperatures and what Windows can and can't read: monitor PC temps from your phone. Building a whole gaming page? See a gaming deck on your phone.
Frequently asked questions
How do I open Windows Performance Monitor?
Press Win+R, type perfmon and press Enter. You can also search Start for "Performance Monitor". It is included in every edition of Windows 10 and Windows 11, Home included. perfmon /res opens Resource Monitor and perfmon /report runs a 60-second system diagnostics report.
What is the difference between Performance Monitor, Resource Monitor and Task Manager?
Task Manager (Ctrl+Shift+Esc) gives a quick live view of CPU, memory, disk, network and GPU and lets you end programs. Resource Monitor breaks the same numbers down per process, file and network connection. Performance Monitor graphs any of hundreds of counters and can log them to a file over hours or days, which is what you want for problems that come and go.
Can Performance Monitor show CPU temperature?
Not reliably. Windows doesn't expose CPU temperature to normal programs on most PCs, so Performance Monitor, Task Manager and SofaDeck don't show it. GPU temperature is a different matter: Task Manager shows it for supported graphics cards, and SofaDeck reads it on NVIDIA cards.
Can I watch my PC's performance from my phone?
Yes. SofaDeck's free PC stat tiles (Windows, 1.0.9 or later) put CPU, RAM, GPU, GPU temperature, disk, network and battery on your phone as live buttons, refreshed about every 1.5 seconds over your home Wi-Fi, so the game or video on the PC stays full screen.