Looking deeper, you may try  cable P/N D385M for cabled HDD configuration, P/N C450M is for R310 server. For hot plug HDD configuration, use cable P/N W846K.  Let me know whether this works for you.
I recently bought a s/h T310 for use as a home server running SmartOS. I didn't realise it had a PERC when I ordered it and I need to get rid of it so I can use 3TB disks in non-RAID mode. I've bought the C450M cable assembly and removed the PERC and associated cable and disk backplance. The disk are connected to data OK, but there is nowhere to plug in P3A on the C450M cable assy. I assume this means I need another cable assembly of some sort that connects power to the disks; however I can find no reference to it anywhere. There was a thread on removing the PERC from a T310 some years ago [URL] however it didn't go as far as connecting the power.
Needing cable to connect power to T310 SAS disks