AHCI enabled in bios question

hey wilders,

ok so i just got a new hard drive and im going to do a clean install of vista 64bit. and im just wondering if the AHCI mode is enabled in my bios, it should install the AHCI driver during windows installation automatically right?

or do i have download some special driver ahead of time in order for the AHCI driver to install?

 

Yep, Windows should set the needed reg settings for AHCI mode if that mode is selected at install.

If Windows is installed and AHCI mode wasn't enabled in bios and you want to enable it then you need to add the reg setting.

http://www.ithinkdiff.com/how-to-enable-ahci-in-windows-7-rc-after-installation/

IMO AHCI isn't of any benefit on a single user system.

 

I've used the reg tweak Franklin linked to.

I bought an SSD drive, and wanted to try AHCI (or was supposed to use it for some reason, can't remember now). Anyway, I applied the reg setting per instructions, rebooted, turned SATA to AHCI mode, saved and rebooted.

I installed fresh onto the SSD, just because. I made an image prior to the AHCI switch. The first time I went to restore my image I got a BSOD. Then a few more times Then I remembered the AHCI was enabled after the image. I changed BIOS from AHCI back to SATA or whatever, then BSOD went away. Then I made the reg tweak again, reset back to AHCI, then made a new image with AHCI turned on. Just an FYI for you.

AHCI allows you to use NCQ (Native Command Queing) if your drive supports it. I would tend to agree with Franklin, that AHCI doesn't do much for you... unless you are using an SSD drive (in which case it give a measurable speed gain, for me anyway).

Sul.

 

Thanks for that bit of info Sully. Gonna grab an SSD soon (I hope) and will have to remember to enable AHCI mode at install.

 

Most modern HDDs also support NCQ, but for home users it is not worth until they run HDD intensive applications.

 

I have tried AHCI in the past, and for some reason chose not to enable it. When I got the SSD and was researching about it, I came to some conclusion that it was needed or was desirable. I was testing read/write performance and do remember it was better with AHCI on, but I think there was a reason for using it. Possibly the intel driver I am using rather than the M$ one mentioned it, or it was needed for TRIM maybe?

Sul.