Thanks a lot for your response, SDH.
The problem I have is that I want to use disks more over 2 terabytes, and the disk controller of z800 don't recognize more than 2T of capacity.
I had the pcie SATA controller in another PC in order to work with 3T and 4T disks, and I'd like it works in my z800.
As I said in my last post, it's pretty strange. The HP z800 seems recognize the pcie SATA controller one in ten or more boots.
Best reggard