Why I built this calculator

And why most bottleneck tools online get it wrong

My story

I have been building PCs since 2015. My first serious mistake was pairing an AMD RX 580 with an FX-8350 — I spent $280 on a GPU that was immediately CPU-bottlenecked at 1080p. The tools I found online at the time just compared benchmark scores on paper. None of them accounted for the game I was playing, my resolution, or my RAM speed.

I started tracking these combinations in a spreadsheet. By 2022 I had over 300 CPU-GPU pairs with real-world FPS data cross-referenced against PassMark, UserBenchmark, and benchmark videos from trusted YouTube channels. In 2023 I turned that spreadsheet into this calculator. I update it every month when significant new hardware launches.

How the calculator works

The tool normalises benchmark scores for both your CPU and GPU onto a shared performance scale, then calculates the performance gap between them at your selected resolution and use case. At 1080p, CPU score is weighted more heavily because the processor handles more game logic at lower resolutions. At 4K, GPU score dominates because rendering load shifts almost entirely to the graphics card. The bottleneck percentage shows how much of your weaker component's capacity is being wasted by the mismatch.

My test setup

Category Details
CPU test range Intel 8th gen through 14th gen, AMD Ryzen 3000 through 7000 series
GPU test range GTX 1060 through RTX 5090, RX 580 through RX 7900 XTX
RAM tested DDR4-3200 and DDR5-6000 dual channel
Resolutions tested 1080p, 1440p, 4K
OS Windows 11, latest drivers as of test date
Database last updated April 2026

What this tool cannot do

Bottleneck calculators estimate — they do not measure your live system. Real-world results depend on your specific game engine, driver version, background processes, and cooling performance. Use this as a planning tool before a purchase, not a live diagnostic. For live diagnosis, use MSI Afterburner to monitor your CPU and GPU usage percentages while gaming.

BD

Bran Deen

PC Hardware Analyst

Building and testing PC hardware combinations since 2015. Creator of the PC Bottleneck Calculator. I update this tool monthly and answer hardware questions sent through the contact form.