Use HDD Controller Card, or On Board SATA?

Hello,

So I will be installing two 5in3 hard drive enclosures this weekend and am considering my drive/SATA configuration/arrangement.

I currently have an IBM Serveraid M1015 SAS/SATA Controller 46M0831, flashed over to JBOD IT mode or whatever it is called. I originally had it for XenServer, in which I passed the entire device through to a VM for my storage VM. Now that I am on unRAID, I don't necessarily need to do this.

I have an AsRock C226 WS, which has 10 on board SATA 6. 6 via the 226 chipset, and 4 via 2 Marvell SE9172.

I currently have 1 parity, 4 data, 1 cache and 2 unmounted. This still leaves me 2 growth slots.

Is there benefit to using the PCIe add in? The on-board? If no benefit to the PCIe, I am sure I could save a few watts and pull the controller. Either sell, or keep as a spare for when I need to go above 10 drives.

All on-board controllers support hot swap. I am not positive if the PCIe card does or not, though I would be surprised if it did not.

Insight appreciated.

Link to board is here: http://www.asrockrack.com/general/productdetail.asp?Model=C226%20WS#Specifications

Random link to card: http://www.amazon.com/gp/product/B0034DMSO6?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00

Until you need the additional ports, I'd just use the onboard ports.  As you noted, you could even pull the card and save a bit of power ... and who knows -- with the size of modern drives you may even find that you don't need the add-in card for quite a while.