Just to help you understand:
"IDE mode" or, more completely, "IDE Emulation Mode" was a convenience offered by many BIOS's in the early days of SATA drives. The issue they were addressing was this: SATA hardware hit the market about the same time as Windows XP did. Win XP has built-in drivers for IDE devices, but did NOT have any built-in driver for an AHCI device. And AHCI is really the way that systems should be using SATA devices. Windows XP certainly did, however, have a way to use AHCI devices - just install the device driver that the mobo maker provided. HOWEVER, the simple way to do that did NOT enable Win XP to BOOT from such a device. Windows still had a way to do that, too - it was part of a long-standing method used for uncommon devices. When you first started on the Install of Win XP from its CD, you are asked whether you had any device drivers you wanted to install as part of the system. (This feature originally was used to install at a low level drivers for devices like SCSI drives and RAID arrays, and it is STILL used if you want to be booting from a RAID array.) The small glitch was that, during the Install phase, Win XP only knew how to load such a device from a floppy diskette, so you had to have a floppy drive in your machine and a diskette you prepared on another machine with the AHCI device driver on it from your mobo maker. Then you could tell Win XP Install (by pressing the F6 key) that yes, you did want to load a device driver and it would let you do that and ask for more until you had no more. Then you could tell it to proceed. The Install process put that driver on the HDD at a low level so that it did become like a "built-in" device driver that Win XP could load very early so that you could BOOT from an AHCI device and use it normally.
Now, many people did not grasp all that, and many people at that time were buying and building machines with NO floppy drive, so that was a problem for some. The solution that became VERY popular was offered in many BIOS's. You could configure some or all of your SATA ports to operate in AHCI Mode if you were prepared to install the AHCI driver "properly". But if you did not want to or could not, you could set your SATA port(s) to "IDE Emulation" Mode. In that mode the mobo would limit the way it used devices on the SATA port(s) to only those commands that an IDE device used, which means you lost a few new features of SATA and AHCI. But then Win XP found what appeared to be simple IDE devices, and used its built-in IDE driver and all was happy!
Beginning with Vista all Windows have had both IDE and AHCI device drivers "built in" so that special F6 route for adding a driver was no longer necessary, and thus neither was the optional BIOS setting. The choice of storage devices from which to load special drivers (like a RAID system driver) also was broadened to include things like USB memory sticks. Since we're now several generations beyond Win XP, it makes sense NOT to continue offering this option.
Facebook
Twitter