The R510 is a 11th generation Dell Server and does not use "channels" and hence no way to "split". The R510 does have 2 SAS connectors but all data travels point to point from the controller to the drives and does not use channels to do so. The last Dell Servers to use SCSI channels were 8th generation Servers. By the way , raid arrays are not limited to connectors and can span the 2 connectors.
On most PE systems there is a way to split the drive backplane to use both SAS channels.  How is this accomplished on a R510?
R510 12 bay system with 2.5" drives