Yes you can.
But I've a question; are the disks in the HDD bays mechanical or SSD's?
I ask, as the ICH (chip that actually contains the SATA ports) has a throughput limit of ~660MB/s, which can be exceeded exceptionally fast when using SSD's simultaneously, such as in a stripe set (you'd end up throttling if this happens = won't get the performance you may be expecting).
The ICH is much harder to throttle using mechanical disks (i.e. ~110MB/s per port <~660MB/s divided by 6x ports>, which is all the fastest 7200rpm SATA mechanical can do right now).