Below are the PerfCap Reasons, along with a brief description to do with what is causing them.
vRel = Reliability. Indicating performance is limited by voltage reliability.
VOp = Operating. Indicating performance is limited by max operating voltage(Hardware Limit).
Pwr = Power. Indicating performance is limited by total power limit.
Thrm = Thermal. Indicating performance is limited by temperature limit.
Util = Utilization. Indicating performance is limited by GPU utilization.
Example here, GPU is not being used, however GPU-z has woken the device. The GPU is not at a higher speed because the GPU usage is low. PerfCap Reason shown in the blue outline below.

vRel = Reliability. Indicating performance is limited by voltage reliability.
VOp = Operating. Indicating performance is limited by max operating voltage(Hardware Limit).
Pwr = Power. Indicating performance is limited by total power limit.
Thrm = Thermal. Indicating performance is limited by temperature limit.
Util = Utilization. Indicating performance is limited by GPU utilization.
Example here, GPU is not being used, however GPU-z has woken the device. The GPU is not at a higher speed because the GPU usage is low. PerfCap Reason shown in the blue outline below.
