I blamed my RTX 4090 for poor performance, but this was the real problem

Upgrading from an RTX 3090 to a 4090 didn't deliver expected performance gains due to a CPU bottleneck from a Ryzen 9 5900X. GPU usage hovered at 70-85% instead of near 100%, causing stutters and lower-than-benchmark FPS, especially in competitive titles at high frame rates. Switching to a Ryzen 7 5800X3D resolved the bottleneck, finally matching benchmark numbers. The key lesson: pairing a flagship GPU with an aging CPU — particularly for fast-paced, CPU-intensive games — will leave significant performance on the table.