Re: Can I add a 2.5" SSD with capacity larger than 2T? The R7 specification says it's capacity cap for 2.5" is 2T. Yes.  Dell only validates up to 2T but user can upgrade to greater.  It is just Dell does not gurantee it would work since they have not tested it. Re:  I may also replace the 3.5" 2T HDD with a larger one.  (It seems that I can only have a single 3.5" HDD there.) Again the specification says the capacity cap is 2T for 3.5" HDD.  Is that true? I didn't see any reason that I could not use a larger 2.5" SSD or 3.5" HDD if the port is there, but I would like to get some confirmation before I buy new storage disks.  same answer.  no worries.  see user benchmark Alienware Aurora R7 Performance Results - UserBenchmark Since R7 can support 3 TB 3.5" hdd, it can definitely support 3TB 2.5" SSD too. 70 more user validated evidences. UserBenchmark: PC Build Comparisons
I already added a M.2 SSD when I bought R7 and now plan to expand the storage. I read the specification but got some questions. 1. Can I add another M.2 SSD rather than replacing the current one? i.e. Does R7 support two M.2 NvMe SSD?  2. Can I add a 2.5" SSD with capacity larger than 2T? The R7 specification says it's capacity cap for 2.5" is 2T. 3. I may also replace the 3.5" 2T HDD with a larger one.  (It seems that I can only have a single 3.5" HDD there.) Again the specification says the capacity cap is 2T for 3.5" HDD.  Is that true? I didn't see any reason that I could not use a larger 2.5" SSD or 3.5" HDD if the port is there, but I would like to get some confirmation before I buy new storage disks.  Thanks!
Aurora R7, SSD and HDD