There are two versions of the PERC 6/i: Integrated and Adapter. Only the Integrated version can go in the integrated storage slot.
I have a PE R710, and l have purchased a PERC 6/i RAID card  When the PERC card is inserted in the internal storage card slot, l get an error that it is an unsupported card. If the card is in any of the other slots, server will boot fine, but the cables are not long enough to connect the SAS drives. The Part Number on the card is 0T774H, doing a google it looks like this card shipped with a bracket, so maybe not originally intended for this server. Any suggestions or am l wasting my time trying to get this to work?
PE R710 error during POST with PERC 6/i card