Bottleneck Calculator
Estimate CPU and GPU bottleneck for your PC build. Select your processor, graphics card, and resolution to see which component is the weak link.
About Bottleneck Calculator
A bottleneck occurs when one component limits the performance of another - typically a weak CPU limiting a powerful GPU, or vice versa. This calculator estimates how well your CPU and GPU pair at 1080p, 1440p, and 4K by comparing relative benchmark scores adjusted for resolution. All calculations run in your browser.
How the Bottleneck Percentage Is Calculated
| Step | What Happens |
|---|---|
| 1. Component scores | Each CPU and GPU has a relative gaming benchmark score (0-100) based on real-world testing data |
| 2. Resolution adjustment | CPU score is weighted more at 1080p (CPU-bound), GPU score is weighted more at 4K (GPU-bound) |
| 3. Bottleneck calculation | Percentage difference between adjusted CPU and GPU scores |
Reading the Results
| Bottleneck % | Colour | Meaning | Action |
|---|---|---|---|
| Under 10% | Green | Well balanced | No changes needed - both components are well matched |
| 10-25% | Yellow | Mild mismatch | Performance loss is minor - upgrade the weaker component when budget allows |
| Over 25% | Red | Significant imbalance | The stronger component is being wasted - prioritise upgrading the bottleneck |
Why Resolution Changes the Bottleneck
| Resolution | Pixels Per Frame | Bottleneck Tendency | Why |
|---|---|---|---|
| 1080p (1920x1080) | 2.1 million | CPU-bound | GPU finishes frames quickly, CPU becomes the limiting factor |
| 1440p (2560x1440) | 3.7 million | Balanced | Both CPU and GPU share the load more evenly |
| 4K (3840x2160) | 8.3 million | GPU-bound | GPU has 4x the pixels to render compared to 1080p |
This is why a budget CPU can work well at 4K (the GPU is the bottleneck anyway) but causes problems at 1080p where the CPU cannot feed frames to the GPU fast enough.
How to Fix a Bottleneck
| Bottleneck Type | Symptoms | Software Fixes | Hardware Fix |
|---|---|---|---|
| CPU bottleneck | Low GPU usage (40-60%), high CPU usage (90-100%), FPS does not improve when lowering resolution | Lower draw distance, NPC counts, physics settings | Upgrade CPU |
| GPU bottleneck | High GPU usage (95-100%), CPU idle, FPS improves when lowering resolution | Lower resolution, turn off ray tracing, reduce texture quality | Upgrade GPU |
| RAM bottleneck | Stuttering despite normal CPU/GPU usage, high RAM usage | Close background applications, reduce texture quality | Add more RAM or faster RAM (especially on AMD) |
Common Well-Matched Pairings
| Tier | CPU Example | GPU Example | Target Resolution |
|---|---|---|---|
| Budget | Ryzen 5 5600 / i5-12400F | RTX 4060 / RX 7600 | 1080p |
| Mid-range | Ryzen 7 7700X / i7-13700K | RTX 4070 Ti / RX 7800 XT | 1440p |
| High-end | Ryzen 9 7950X / i9-14900K | RTX 4080 / RX 7900 XTX | 4K |
| Enthusiast | Ryzen 9 9950X / i9-14900KS | RTX 4090 | 4K with ray tracing |
If you are building a new PC, the PSU calculator helps size your power supply. For comparing memory kits, the RAM latency calculator shows true latency in nanoseconds. All calculations run in your browser.
Frequently Asked Questions
How accurate is this bottleneck calculator?
This tool provides a rough estimate based on relative benchmark scores. Real bottlenecks vary depending on the specific game, graphics settings, RAM speed, background tasks, and driver versions. Use it as a starting point, not a definitive answer.
What does bottleneck percentage mean?
The percentage shows how far apart your CPU and GPU performance are at the chosen resolution. A lower number means a more balanced system. Under 10% is considered well matched.
Why does resolution affect the bottleneck?
At lower resolutions like 1080p the CPU has to work harder because the GPU finishes frames quickly. At 4K the GPU does most of the heavy lifting, so a slower CPU matters less.
Is a small bottleneck bad?
Not necessarily. A bottleneck under 10-15% is perfectly normal and will not noticeably affect your experience. Only large mismatches, like pairing a budget CPU with a flagship GPU, cause real problems.
Should I always pair equal-tier CPU and GPU?
In most cases yes, but it depends on what you do. Content creators may want a stronger CPU, while gamers at 4K can get away with a slightly weaker one. Match your hardware to your actual workload.
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