Dell optiplex 380 ahci mod please?

[hoobix]

Hi, according to my computers manual and other users this machine (Optiplex 380) should support the changing of sata emulation modes. 
It however, does not. I have thoroughly checked. If a user would mod the bios to allow for this (I am pretty sure the sata controller is capable of this) I would be eternally thankful. 

I am using this bios, it has microcodes for xeons.

https://www.sendspace.com/file/34i5ta