A GPU bottleneck occurs when graphics rendering is the main limit for a workload. It is common in visually demanding games and at higher resolutions, but GPU usage should be interpreted together with frame rate, clocks, temperatures and settings.
High GPU utilization is not automatically a problem
Near-full GPU utilization can simply mean the graphics card is being used effectively. If you are reaching your target frame rate, there may be no practical problem to solve.
Resolution and graphics settings
Increasing resolution, rendering quality, ray tracing and other visual effects generally increases GPU workload. Lowering these settings can reduce GPU frame time when the graphics card is the limiting component.
Watch VRAM as well
Video memory usage can matter when a game approaches the available VRAM capacity. Monitor VRAM alongside GPU utilization and frame-time behavior rather than treating one metric as a complete diagnosis.
When should you upgrade?
Consider a GPU upgrade when the graphics card consistently limits the experience in the workloads you care about and your CPU, RAM, cooling and PSU are otherwise suitable.