Serial Advanced Technology Attachment (SATA) is a computer interface used to attach hard drives. The basic input/output system (BIOS) on the Dell Precision is a small program contained on the motherboard that enables users to change hardware settings via a simple graphical user interface (GUI). Users can change the SATA operation of drive to advanced host controller interface (AHCI) to improve hard drive performance.
The Dell Precision includes an option in the BIOS to change the SATA operation, or SATA mode. SATA devices can run in ATA, AHCI or RAID mode. ATA mode lacks the features of AHCI, but is compatible with older operating systems. AHCI works with modern operating systems, like Windows Vista and Windows 7, and has extra features ATA lacks. RAID mode can run on Windows XP and Windows 2000 if the proper drivers are loaded at setup, and enables users to set up a multi-drive configuration to improve disk performance.
AHCI isn't compatible with Windows XP or older editions of Windows. SATA devices perform better when configured as AHCI, rather than ATA; AHCI reduces the time it takes to save and open files on the hard drive via the native command queuing (NCQ) feature, which optimizes multiple read/write commands. AHCI also allows hot plugging, a feature which enables users to swap out hard drives while the Dell Precision is still on.
ATA mode should be used when running older operating systems on a SATA hard drive. The SATA device emulates ATA -- also known as Parallel ATA (PATA) or integrated drive electronics (IDE) -- technology. SATA was developed in 2003, after ATA devices had been in common use for about a decade. Therefore, while ATA devices have the most compatibility with all operating systems, it doesn't have the same performance or features as AHCI, a newer technology.
You can change the SATA operation in the Dell Precision BIOS. Press "F2" on the Dell logo screen, then expand "Drives." Click "SATA Operation." Select "AHCI," "ATA" or "RAID" from the options. Some Precisions might not have the option for RAID, while others will have options such as "RAID Autodetect/AHCI" or "RAID Autodetect/ATA." Click "Apply." Press "F10" to save and quit.