How to check if AHCI mode is properly enabled?

I selected AHCI mode in the BIOS and upon restarting Windows got some updates including what appeared to be for AHCI. However, is there a way to definitively check that AHCI is the mode being utilised or is simply ticking it in the BIOS proof in itself?

Thanks,
Michael

Change the bios back to IDE and see if Windows still boots, if it doesn't then that means ACHI was enabled.

I'll give that a go a bit later then when I've finished messing with everything else (just done a fresh reinstall).

Is there any major advantage to running in AHCI mode? I've got all my PCs and the Home Server loaded up in IDE mode....

AHCI offers (small) performance benefits.