Bottleneck Checker

A free, open-source CPU and GPU bottleneck checker. Pick a processor and a graphics card and it tells you whether they hold each other back - as an honest range, weighted by resolution and game type, instead of a fake single percentage.

Live demo:bottleneckpc.github.io/bottleneck-checker

Built and maintained by BottleneckPC. The full bottleneck calculator on the site adds build recommendations, live prices, and per-game FPS.

Why another bottleneck calculator?

Most of them spit out one confident-looking number ("your PC has a 17.3% bottleneck"), which no real benchmark could ever back up. Hardware doesn't behave that way: the same CPU + GPU pairing looks CPU-limited in a competitive shooter and GPU-limited in a ray-traced single-player game, and different again at 1080p versus 4K.

So this tool does three honest things instead:

• Reports a range, not a fake decimal. "GPU-limited by 15-22%, depending on the game."
• Weights by resolution and genre. Esports and simulation lean on the CPU; AAA leans on the GPU; higher resolutions shift load to the GPU.
• Models DLSS/FSR. Upscaling renders internally lower, shifting work back to the CPU.

Features

• 300+ CPUs and 140+ GPUs, calibrated on a 0-100 gaming scale
• Resolution (1080p / 1440p / 4K), game-type, and upscaling controls
• A signature CPU-to-GPU balance meter with confidence and load-share readouts
• Rough FPS estimate at the chosen settings (an honest range, not a benchmark table)
• Shareable results via URL (?cpu=...&gpu=...&res=1440p)
• No build step, no framework, no tracking

Use it

It's plain HTML/CSS/JS. Clone and open index.html, or serve the folder:

git clone https://github.com/bottleneckpc/bottleneck-checker.git
cd bottleneck-checker
python3 -m http.server 8080 # then open http://localhost:8080

Deploy anywhere static (GitHub Pages, Netlify, Cloudflare Pages) - it's a folder of files.

Embed / reuse the engine

The scoring model lives in engine.js as dependency-free ES modules:

import{scoreVerdict,estimateFPS}from'./engine.js';constv=scoreVerdict(97/* cpu score */,82/* gpu score */,'1440p','aaa');// => { type: 'balanced', pct, range: { low, high }, confidence, cpuPct, gpuPct }

About the data

The hardware list in data.js is a static snapshot taken from bottleneckpc.com. The app makes no network calls - it can't be used to hammer anyone's server, and it works fully offline. Scores are calibrated gaming ratings, not raw synthetic benchmarks. The snapshot date is noted at the top of the file; open an issue or PR to refresh it.

Contributing

PRs welcome - new or corrected hardware entries, engine tuning, accessibility, and translations especially. Keep it dependency-free and framework-free.

License

MIT - do what you like, just keep the notice. Built by BottleneckPC.