Looks like Raid-C if your underlying storage is striped.  snippet from h7139-implementation-planning-vplex-tn.pdf.    When creating a device the underlying storage should be taken into account. If the underlying storage volume has RAID 0 or stripe properties from the storage array, the VPLEX administrator should use that storage in a device with RAID 1 or RAID-C properties (not RAID 0 properties). This is to avoid reverse mapping of RAID 0 or stripe, which could create hot spots on the spindles underneath it all. 
 Would like to bring this discussion back up. Recently, we did some testing on a read intensive lun on AIX (VIO/LPAR) that clearly shows Raid-C on the Vplex using 2x200GB extents, creating 1x400GB lun was not only faster, but would sustain MB/s over same lun that was created Raid-0 on Vplex. With Raid-0 we are attributing it to Vplex striping on Vmax striped thin pools handicapping the pre-fetch algorithm of the Vmax array.  Note - we use thin pools on the Vmax and create 200GB tdevs to encapsulate into the Vplex.    For Vmax customers using thin storage pools with Vplex, what are customers defaulting to for Vplex Raid type?  Raid0, RaidC, 1:1 ?  
Vplex raid options