Dragonfly 7 - New installation

I just get a new dragonfly7 , ( version E70231 gold )

1- I got tne navionics map with the sonar but the capacity of the SD card included is only 4 GB, will it be enough to keep datas ? ( If datas are saved on the SD card instead of in the internal memory of the sonar ???)

2- Should I do an upgrade of software before the installation , is there a real benefits ?

Thanks