Windows 7: AHCI : Enable in Windows 7 / Vista

Hello LM2008.



Yes, starting at step #3 and finish what the tutorial says to do.

no AHCI drivers message appeared or asking to restart, is there anyway to verify is active?

Howdy.


After you changed the registry value in step #3 did you re-start the PC and change it to "AHCI" like in step #4 below?

yes

Just an update of what I found out about ahci performance! After I installed and got ahci working I checked for any performance change in Windows 7 hard drives. My drive performance before I changed to ahci was 5.4 and after the change it was still 5.4. I then installed a SSD as my C drive and my drive performance went from 5.4 to 7.1! If I would have known this before I started I don't think I would have changed to ahci. So my advice to anyone wanting to increase the drive performance on their system would be to go out and buy a SSD.

The WEI is not a good benchmark.

If you what a more accurate benchmark use HD Tune or Crystal Disk.

AS SSD Benchmark is a good one for SSDs.

It will also depend on the specs of the HDD and SSD. An older SATA drive may not be able to directly use some of the benefits.
A WEI of 5.4 tells me it may be an older model or have other issues. A 'Green' version uses less power and has less performance.
For the best performance get a 7200 RPM, 32 MB cache, HDD. Be sure it is SATA 2 and supports NCQ, S.M.A.R.T. and Plug and Play.

There're other benefits like NCQ Native Command Queuing, will get the data faster with less wear on the HD. Plug and Play, if you need it, ie external HD. As mentioned earlier.

The best benefit with a SSD is AHCI will enable Trim when using Windows 7.

Some SSDs will seem to have better specs but will get lower benchmarks and WEI score due to the I/O rates.

And here I am quoting myself, yet again... Lol.

Anyway, I ran into a few issues with trying to switch to RAID; my BIOS won't allow me to change my boot order when RAID is enabled... Everytime I try set my DVD drive as first boot device, when I go back into my BIOS my RAID array is back at the top of the list. I figure it's either an issue with my DVD-RW using a SATA interface, my BIOS version (1.6), or in the worst case my physical BIOS chip.. Hopefully a BIOS flash to 1.7 will sort it out, I'll see tonight.

Dave76

Thanks for the information, I will try the other benchmark tools you listed and see what kind of score. I have four SATA drives on my system of different ages so that may be causing the low scores.

Your welcome, run the benchmarks on the HDDs and post them on the Show us your hard drive performance thread.

And your SSD on the Show us your SSD performance thread.

You might see some performance improvement by moving your OS to the fastest HDD, or obviously to the SSD, if your running only one OS.

Thank you so much for this info. After getting a Sata Dvd-Rw I was having a lot of buffer problems and I noticed that my bios was set to IDE. I changed to AHCI and Windows7 said it could not boot

I had to change back to IDE. This allowed me to boot back to windiows and checked this forum for any solution. There was my life saver information. I quickly followed this tutorial and my windows was back up and running.

Excellent info. Keep up the good work.