Hello blackwing,   As of now : No Dell drives are dual actuator. No PERC supports dual actuator drives yet. This could change in the future.  
I recently bought a 2nd hand Dell poweredge R720xd with PERC H710P mini as its raid controller and then I put Seagate Exos 2X14 14TB (2x 7TB) SAS 12Gb/s 3.5" Enterprise HDD (ST14000NM0081).Is this drive compatible with the RAID controller? because instead of showing 14TB as my storage it only shows 6.519TB. 
R720XD - Seagate Exos 2X14 14TB (2x 7TB), issue?