Large Filesystem I/O performence

Hi,

I am going to make fresh installation RHEL 7.1 with ext4 filesystem. I will use data disk on storage (EMC) I want to know which better for I/O performence: many disks total 10TB (example 20 numbers 500GB disks) or one disk (10TB)

Note1: In future this system will require more capacitiy.
Note2: SAP with Oracle will run on this system.
Note3: Backup solution is Symantec Netbackup.