All the info is here: [URL] Although it is not all laid out in a nice chart - you'll have to read all the documents to get the answers. Easier way? Ask here.   In general, parts are designed to compliment tech in the server, not provide backward compatibility for older, less advanced hardware. The 2950 takes the PERC 5/i, PERC 6/i, SAS 5/iR, and SAS 6/iR. The R710 can take a PERC 6/i and SAS 6/iR, but also uses the S300, H200, and H700 controllers. PERC 5 and PERC 6 use an SFF-8484 connector; the PERC H200 and H700 use an SFF-8087 connector. Batteries should be the same, but cache size and type are different (PERC 5/6 have 256MB; H700 has 512MB and 1024MB).  
Does anyone have a good link that explains the differences of Dell RAID Controllers and accessories?   Example.  Does the same controller work in the Dell 2950 as R710?  How are the cables different?  Are batteries and cache different?   In general trying to figure out what crosses from one server to the next in the Dell RAID Department.   Thank you
RAID controllers