How to populate dimm slots on DL160G5?

Hi forum,

any memory professional over here? I've got a DL160G5 with 4GB memory, 4 modules in slots 1, 3, 5 and 7. These are single rank modules (part no. 398707-051). Now memory must be extended to 16GB, but I'm not sure about how to populate the  slots. Is it ok to populate slots 2 and 4 with 2GB modules and slots 6 and 8 with 4GB modules?

Thanks for a hint,

Stefano