Hi, thanks for choosing Dell and I hope this information helps:

How to Manage the QSFP Ports on a Dell EMC Networking S4810 Switch

     https://dell.to/3iwFW7V

1. Splitting a QSFP port into 4 x 10Gb SFP+ ports
2. Verifying the 1 x 40Gb or 4 x 10Gb ports are available
3. Setting the 4 x 10Gb split ports to a 1 x 40Gb QSFP port, the default setting.