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Bottleneck Calculator
Find out what is really limiting your frame rate. Use readings from your own game for a real answer, or a quick estimate if you are planning a build.
Read these from a performance overlay during a busy moment in the game.
A rule of thumb, not a measurement. Use "Check my PC" once it is built.
Why there is no bottleneck percentage
Many calculators give you a single number, such as "your CPU bottlenecks your GPU by 17%". That number cannot be worked out from a parts list. The part that limits you changes from game to game, and with your resolution, settings and target frame rate. Your own readings show what is actually happening, so we use those instead.
How the checker reads your numbers
- GPU near 95 to 100%: your graphics card is doing all it can. That is normal and usually what you want.
- GPU well below 90%, frame rate below your target, and one CPU core near its limit: the CPU is holding things back.
- GPU low and no core near its limit: something else is likely limiting you, such as a frame cap, the game engine or memory.
- At or above your target: nothing needs fixing.
Frequently asked questions
Why doesn't this give me a bottleneck percentage?
Because a single percentage cannot be measured from a parts list. The limit changes with the game, the resolution, your settings and the frame rate you want. A tool that says "your CPU bottlenecks your GPU by 17%" is guessing. Your own GPU usage and frame rate show the real answer, so the checker uses those.
Where do I find GPU usage and FPS?
Turn on a performance overlay while you play. NVIDIA users can use the NVIDIA App overlay, AMD users can use the Adrenalin overlay, and Windows has the Game Bar (Win + G). MSI Afterburner works with most cards. Note the numbers during a busy part of the game, not a menu.
Is a bottleneck always bad?
No. Every PC is limited by something. It only matters if the limit stops you reaching the frame rate you want. If you are already at your target or your monitor's refresh rate, there is nothing to fix.
Why does my CPU look fine when I am CPU limited?
Most games lean on one or two main threads. Overall CPU usage can read 40% while one core is maxed out. That is why the checker asks for your busiest core, not the average.
Will a faster CPU raise my FPS at 4K?
Usually only a little. At 4K the graphics card does most of the work, so a GPU upgrade has a bigger effect. At 1080p with a high refresh rate, the CPU matters much more.
Sizing a power supply as well? Try our PSU wattage calculator.