Identity Gate Timing Discrepancy

Question

I have been examining problems where gate timing is important. When implementing an identity gate, the issue of timing has resulted in a few verification experiments to compare the gate time to that of a u3(0,0,0) gate. According to the source code, the identity gate should be equivalent to a u3(0,0,0) gate; however, when comparing a series of identity operations via a Ramsey experiment to a series of u3(0,0,0) operations, they do not match up. It appears that the identity gate is approximately half the time of the u3 gate. While I have been able to verify the timing through experiments, my concern is that there seems to be a discrepancy between my experiments and the documentation. Can someone please verify my findings?