How segio working in open process?

[bohan12]

Hi I am a beginner of earth science researcher, first thanks for your amazing open source packages, it really helpful in my research process. And tow of questions I want to ask.

First question, I got a problem of segio.open(), what segio doing in open step, it scan part of segy data?

Second question, I use the data in Cloud service and the normal download speed is around 70m/s(by monitor system report), but when I use segyio to open the data only have 20m/s. This cause the bytes read each time?

Thanks for your reply.