CX4 cross connect between SPA and SPB

i got a CX4-120 box , 4 fibre channel connection to SPA and SPB .

Server A  -connected to SPA and SPB

Server B -Connected to SPA and SPB

i'm running cluster and all my live lun running on SPA only. SPB lun is for backup purpose.

i wish to allow my SPB connection to gain access to SPA and load balance between them.

i got power path installed, but seems it doesnt work at all.