How to Check for CPU and GPU Bottlenecks in Your PC

If you’ve ever noticed your games stuttering, apps freezing, or your PC not performing as expected, you might be dealing with a bottleneck. A bottleneck happens when one component, usually the CPU or GPU, becomes the limiting factor that prevents the rest of your system from performing at full potential.

For example, a powerful GPU paired with an entry-level CPU can result in the graphics card sitting idle while waiting for the processor to catch up. The same thing happens if you have a strong CPU but a weak GPU. Identifying bottlenecks helps you make smarter upgrade decisions and optimize your performance.

In this guide, we’ll show you exactly how to check for CPU and GPU bottlenecks on your Windows PC using built-in tools and trusted third-party utilities.

Check for CPU and GPU Bottlenecks in Your PC

Below are the most reliable methods to find out if your CPU or GPU is holding back performance.

1. Check CPU and GPU Usage in Task Manager

The easiest way to spot a bottleneck is by watching resource usage.

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Go to the Performance tab.
3. Check CPU usage and GPU usage while running your game or application.

How to interpret results:

• CPU at 90-100%, GPU below 70% → CPU bottleneck
• GPU at 90-100%, CPU below 70% → GPU bottleneck
• Both at 90%+ → Your system is fully utilized (balanced workload)
• Both under 70% → Software or settings issue (not hardware)

Task Manager provides a quick snapshot, but deeper analysis requires more precise tools.

2. Use MSI Afterburner to Monitor Real-Time Usage and Frame Times

MSI Afterburner is one of the best tools for analyzing CPU/GPU performance.

Set up MSI Afterburner:

1. Download MSI Afterburner and RivaTuner Statistics Server (RTSS).
2. Open Afterburner and click the Settings icon.
3. Go to the Monitoring tab.
4. Check the boxes for:
   • CPU usage per core
   • GPU usage
   • GPU clock
   • CPU clock
   • RAM usage
   • Frame time
5. Enable Show in On-Screen Display.

Now launch your game or application.

How to understand it:

• If GPU usage stays below 70% but one or more CPU cores stay at 95-100%, you have a CPU bottleneck.
• If GPU usage stays between 95-100% but CPU usage is low, you have a GPU bottleneck.
• High frame times (spikes) also indicate CPU bottlenecks.

MSI Afterburner gives you the clearest view of what’s limiting performance.

3. Check CPU Core Utilization, Not Just Overall Usage

A CPU bottleneck doesn’t always show as 100% overall usage because Windows averages usage across all cores.

1. Open Task Manager.
2. Right-click the CPU graph.
3. Select Change graph to > Logical processors.

This separates usage by core.

What you’re looking for:

• If one core is maxed out, that causes a bottleneck even if overall CPU usage is low.
• Games often use one heavy thread, creating a per-core bottleneck.

This is one of the most common bottleneck scenarios in gaming.

4. Check GPU Utilization Using Windows Performance Monitor

For deeper built-in analysis:

1. Press Windows + R, type perfmon, press Enter.
2. Click Performance Monitor.
3. Click the green + icon.
4. Add:
   • GPU Engine → Utilization
   • Processor → % Processor Time

View the real-time graph while running your app or game.

Results:

• GPU engaging all engines at high usage → GPU-bound
• CPU engine pegged at high usage → CPU-bound

This tool provides accurate system-level readings.

5. Check FPS Scaling by Lowering or Increasing Resolution

This simple test helps you understand whether the CPU or GPU is struggling.

Try this:

1. Run your game at 1080p.
2. Run it again at 720p.
3. Compare the frame rate differences.

Interpretation:

• FPS stays the same at both resolutions → CPU bottleneck
• FPS increases significantly at lower resolution → GPU bottleneck

Lower resolution reduces GPU load, so if performance doesn’t improve, your CPU is holding things back.

6. Check for RAM Bottlenecks (Related Scenario)

Sometimes the bottleneck isn’t CPU or GPU but RAM.

1. Open Task Manager > Performance.
2. Check RAM usage.

Signs of a RAM bottleneck:

• RAM usage above 90%
• Disk usage spiking due to paging
• Stuttering even when CPU/GPU usage is moderate

If this happens, your system may need more RAM.

7. Check Bottlenecks Using In-Game Benchmark Tools

Many modern games include built-in performance benchmarks.

1. Look in the game settings for Benchmark or Performance Test.
2. Run the benchmark and review the results.

These often provide average FPS, CPU time, GPU time, and frame-time consistency.

Interpretation:

• CPU time larger than GPU time → CPU bottleneck
• GPU time larger than CPU time → GPU bottleneck

This is one of the most accurate methods for game-specific analysis.

Wrapping Up

Checking for CPU and GPU bottlenecks helps you understand what’s truly limiting your PC’s performance. Whether you’re gaming, streaming, or running resource-heavy applications, bottleneck analysis guides you toward smarter upgrades and better optimizations.

If your CPU is the bottleneck, you can reduce background apps, increase game resolution (counterintuitive but works), or upgrade the processor. If your GPU is the bottleneck, lowering graphics settings or upgrading your graphics card will help. And if neither is maxed out, the issue may lie with RAM, storage, or software configuration.