Even though they look exactly the same, one of these modular controllers is not like the other.....apparently.

Top: Dell P/N Y159P Perc S300 RAID controller

• This controller is a software RAID controller with no cache or battery backup. It supports RAID 0,1,5,and 10. It supposedly supports JBOD though I was unable to get a pass through to FreeNAS or Windows.

Bottom: Dell P/N HM030 SAS 6/iR HBA

• This controller is a hardware RAID controller and HBA. It supports RAID 0 and 1 with the capability to pass through HDD to the OS. If you're looking for a cheap modular HBA for a Dell server that will pass the hard drives through to a FreeNAS install, this would be the controller you want. It's cheaper too (I found it for about $6 on eBay)