In Lossless, 1 hour of SVO files will be making a file of 180GB in size.
In H264/H265, using the API, you can change the bitrate that will directly impact the size of the file.
By default, the higher the bitrate, the higher is the quality of the video.1 hour of SVO file will be around 7GB.
These numbers are based on HD2K@15FPS.
The bandwidth is about the same for the other resolution since you have a higher FPS. (HD2K@15 == HD720@60).
Of course, if you record at HD720@15, the file size will be divided by 4.
Note: .svo is the file type of the videos that are recorded by the ZED cameras.