I am thinking of building a cheap home server and found a server chassis which holds 12 SATA drives.

I'm looking at this [motherboard](http://www.newegg.com/Product/Product.aspx?Item=N82E16813182252), but I am having a hard time understanding how to fit 12 drives onto it.

It has 6 onboard SATA ports for storage, which means I have to buy some sort of expansion card to fit the other 6. The PCI-e interfaces supported by this motherboard are two x8 and one x4.

I decided I want to use RAID 10 on the array.

Three questions:

* If I'm using the 6 onboard SATA ports, does it make sense to buy RAID cards to support the other 6 drives? Is it either using RAID cards for all 12 of the SATA drives or none?
* Will PCI-e 2.0 work with either PCI-e x8 and PCI-e x4? I'm looking at this [raid card](http://www.newegg.com/Product/Product.aspx?Item=N82E16816115075) which seems cheap. I could buy 3 and that would solve the problem. (the same question applies to SATA expansion cards)
* Does it matter if the PCI-e SATA expansion cards use SATA 6 Gb/s while the onboard uses SATA 3 Gb/s in a raid 10 setting?