GPU Bottleneck Estimator
Get a rough read on whether your CPU or GPU is the slowest link at your chosen resolution — an estimate for shopping advice, not a benchmark.
The estimator compares relative performance scores of your CPU and GPU weighted by resolution. It flags obvious mismatches (a 4090 with a 12100, or a 3060 with a 14900K) so you know where upgrade money would actually land.
Honest limits: real bottlenecking is engine-specific, per-core, and varies by scene. Treat the verdict as a direction, not a diagnosis.
How it works
Each tier carries a relative performance score. A resolution factor discounts GPU load as pixels climb (GPU work scales with pixels, CPU work mostly doesn't):
cpuShare = gpuScore × resFactor ÷ (cpuScore + gpuScore)
A >55% share is read as CPU-bound; <42% as GPU-bound inside this heuristic.
Example
RTX 4090 + Ryzen 5 5600 at 1080p: the GPU score swamps the CPU, so the CPU pair is the wall. At 4K the 4090 workload rises and the balance shifts GPU-side.
The math behind it
share = scaledGPU ÷ (scaledCPU + scaledGPU) — heuristic, not a physics model.
Frequently Asked Questions
Is "bottleneck percentage" a real thing?
Yes as a concept — at any instant one part peers the others. The precise percentage is engine-dependent; no estimator can nail it without profiling your game. This tool gives a directional estimate.
Why does resolution change the verdict?
Frames scale with resolution: doubling pixels roughly doubles GPU work but barely changes CPU work. CPU-bound at 1080p can become GPU-bound at 4K — the resolution selector models that shift.
What should I upgrade first?
Whatever falls below 45% balance at your resolution. If the GPU is the wall, upgrading it adds frames; if the CPU is, it won't.