During operation, NVIDIA GPUs automatically manage their PCIe speed behavior based on the current clock usage and power consumption to achieve power-saving efficiency.

This mechanism is referred to as GPU Performance State, or P-State for short.

Since each GPU has different clock ranges, power requirements, and computational capabilities, their respective P-States also vary.

Therefore, if you observe that your GPU is only running at PCIe Gen3 during testing, there is no need for concern—this is normal behavior.

It could be because the current GPU and memory clock or power usage does not require PCIe Gen4 performance at that moment.

Additionally, when the GPU is idle or under low usage, it enters a low-power state, causing the PCIe speed to drop to its minimum.