Sata Mode AHCI / IDE

[Serpentz]

Hey everyone. I hope everyone is doing fine. I've literally rebuilt my entire machine but I think I made a mistake before installing Windows 7.

I should have gone over the BIOS with a fine tooth comb, but I did not. The SATA mode is set to IDE instead of AHCI or RAID and now of course, I can't switch it to my knowledge without getting a BSOD. It means I would have to reinstall the OS over again.

I have been reading up online and did a search here, but didn't find the appropriate thead. I have two questions. I read on a forum somewhere, where an Intel user used a program to change this in Windows somehow. Is there some kind of utility that will allow me to switch to AHCI mode without reinstalling Win7 64bit?

Second question, is it worth it to switch over? I see the benefits are this:

AHCI mode brings 3 main advantages:
Supports NCQ (Native Command Queuing) allowing SATA drives to accept more than one command at a time and dynamically reorder the commands for maximum efficiency.
Supports hot plugging of devices
Supports staggered spin ups of multiple hard drives at boot time

My machine seems kind of slow when accessing data and don't know if this is an issue with the SATA drives being in IDE mode. I got some choppiness in some games that's coming from access data (tested) and that seems weird but could definitely come from SATA drives being in IDE mode.

I got an MSI R5770 Hawk Video card...I'm freaking in love with that thing

I have two Hitachi 7200RPM SATA and one Seagate Barracuda 7200RPM SATA drive. All three are 500GB

My new machine is ASRock M3A770DE Mainboard and I successfully unlocked the 4th core on my AMD Athlon 445 making it a Phenom X4 3.1 and it's running beautifully. Ran a stability test and it was perfect.

RAM is Kingston HyperX CAS8 running at 1600mhz

So my question....to AHCI or not. Do you think its worth it. Have you noticed huge performance gains.

So now I guess I better update my profile and sorry I haven't been around. Me and SevenForums had an email issue

Cheers!

 

[WH4K]

That's weird. I thought Windows 7 handled switching to AHCI mode better than that. Guess it has the same problem as XP.

Anyway, quick answers to a couple of your questions:

1) There is nothing magical about AHCI. About all you will gain is the ability to hot-plug drives. That may be worthwhile if you use an external HDD connected by eSATA. Otherwise, I wouldn't worry about it.

From what I've read, NCQ is only of real benefit in an environment where the disk is being accessed constantly, such as server. Normal desktop users probably won't see any measurable benefit.

The staggered spin-up thing probably doesn't matter either. Maybe it would, if you were running a large RAID (like maybe a 6-disk RAID 10) and had a barely-adequate power supply.

2) Yes, there should be a way to install the AHCI drivers so that Windows 7 doesn't bluescreen on startup. I did it with Windows XP, although it wasn't all that straightforward. I didn't have to reinstall Windows XP, and you shouldn't have to reinstall Windows 7 either.

update:

Just for curiosity, I tried switching my disk controller to IDE mode. Windows 7 booted, but then made me reboot immediately, presumably because it had to install the IDE-mode drivers for the disk controller. On next startup, I re-ran the Windows Experience Index test. My disk score remained exactly the same (5.9) as when I had the disk controller in AHCI mode.

I then restarted, got into the BIOS menu & switched the disk controller back to AHCI mode. On restart, Windows 7 again booted fine.

 

[Serpentz]

Hey thanks for the reply. I'll try to see if I can switch and see what happens. I don't think the Windows Index would change unless you replaced the drive with a solid state. 5.9 seems to be the best score you can get with a conventional hard disk.

Thanks for the reply.

 

[WH4K]

It might be informative if I ran a hard drive benchmark utility with the disks in both AHCI mode and IDE mode.

What would be a good testing utility? HD Tach has a trial version that will test for best-case (sequential) read speeds, which should be enough to show any differences between AHCI and IDE performance.

I didn't know mechanical HDD's could only score 5.9 on the Windows index. How about if you have them in a RAID 0 config? RAID 0, or one of its hybrids such as 1+0, can just about double read speeds in many cases.

I'll post results if I do get around to some testing.

Practically no difference, which is about what I expected.

 

[steve-pressman]

Here you go my Man excellent tutorial for you from our very own Bare Foot Kid

http://www.sevenforums.com/tutorials/61869-ahci-enable-windows-7-vista.html?filter[2]=Performance%20Maintenance


Steve

 

[DeaconFrost]

There are ways of swapping, but don't bother if you are going to expect a performance difference, because there won't be, not with a spinner.

 

[Serpentz]

I just tried to switch...BSOD. So it's not possible anyway and for no performance gain, it's not even worth it to reinstall the OS.

Thanks for the replies everyone.

 

[essenbe]

It is possible, I have done it before. Just follow the tutorial Steve Pressman gave. But, I don't believe you will see much performance gain unless you have an SSD.

 

[unifex]

This seems to depend on the BIOS and on the motherboard. I have posted my experience in the tutorial thread Steve mentioned, but let me repeat briefly. I have a Dell Inspiron 530, which I have upgraded to its max. When I bought a SSD, I decided to enable AHCI for it based on many accounts in these Forums and elsewhere. Trouble is, Dell Bios is very restricted, the only thing one can do is to switch from IDE to RAID. That (although not obviousl beforehand) does turn on AHCI. But, as much as I tried to enable AHCI in my old installation of Windows 7, I did not succeed. No matter what I do, if I boot the old Windows installation (installed for IDE) with the RAID/AHCI setting in the BIOS - the system will not boot, no BSOD, but right after initial animation the machine will reboot on its own. So for now I have to switch the BIOS setting every time I need to turn on another OS.

In addition, the eSATA experience also seems to be affected by this BIOS setting. Of course, my Dell mobo does not have a on-board eSATA, so I use a PCI-e card (made by Hama) with a JMicron chip. This is a RAID/AHCI card. Now, when I boot in IDE and then plug the external drive into the eSATA port on this card - everything works as advertised, although a bit slower than on my laptop which came with a native eSATA port. Now, if I boot into AHCI, then plugging the external drive into the eSATA card does not work. I am not sure if the two AHCI controllers are in conflict or something, I have not had the time yet to investigate this properly.

Now, since I am running two setups, one in IDE and one in AHCI, I can say that there is basically no difference between them, in every-day use. Of course, for the SSD AHCI is supposed to be better because of TRIM support, but that's "under the hood". On the surface, the SSD is definitely faster than HDD, although so far not as screaming fast as I believed it would after reading all the threads about them. But then, like I said, I only had very little time to play with the thing.

 

[Dave76]

I would recommend AHCI, you might not notice a performance improvement, but NCQ can reduce the HDD activity and disk thrashing.
If you're using eSATA it's nice to be able to remove the external when you want to.
The tutorial listed by steve-pressman does work very well.


@unifex, I switched from IDE to RAID on my Dell Inspiron 530, before the reg edit trick was known. Loaded the RAID drivers and when it asked to re-boot I went to the BIOS and switched it to RAID, after the OS loaded it asked for another re-boot and I was in AHCI mode.

If this doesn't work for you, use the above tutorial.

As long as you have the RAID drivers loaded in the OS it will run in AHCI mode.
When it re-boots by itself does it run fine afterwards?

I never used a PCI-e card, got a SATA cable that went to a backplate with a eSATA plug on it, nothing else just cable.
Works great for over three years now, can hot swap with a nice little program called "HotSwap", it looks and functions just like the MS Safely Remove Hardware option, except it will clear the cache and let you unplug the external.
This method will also let you run an OS from an external, it has no way of knowing it's not internal.

If your SSD is not noticeably faster, there might be something that is holding the performance back. Bad alignment, old drivers, there are several things that could be doing it.

 

[unifex]

@unifex, I switched from IDE to RAID on my Dell Inspiron 530, before the reg edit trick was known. Loaded the RAID drivers and when it asked to re-boot I went to the BIOS and switched it to RAID, after the OS loaded it asked for another re-boot and I was in AHCI mode.

If this doesn't work for you, use the above tutorial.

As long as you have the RAID drivers loaded in the OS it will run in AHCI mode.
When it re-boots by itself does it run fine afterwards?

Well, that's the thing, it does not, it simply keeps re-booting. And the tutorial is what I followed. I downloaded the latest drivers from Intel, installed, and it did not even ask me to re-boot. So I went ahead and re-booted and changed the settings in BIOS and now I have what I have.

Out of curiosity, which drivers did you install exactly?

If your SSD is not noticeably faster, there might be something that is holding the performance back. Bad alignment, old drivers, there are several things that could be doing it.

Well, it's clearly faster. It's just that when I run the OS off the SSD I don't get the "wow" factor. Maybe this is because I moved all temporary files, user files profiles and other places where Windows writes a lot off the SSD in an attempt to reduce the write cycles.

 

[DeaconFrost]

I would recommend AHCI, you might not notice a performance improvement, but NCQ can reduce the HDD activity and disk thrashing.
If you're using eSATA it's nice to be able to remove the external when you want to.

We should clear up a few things here. You are correct about the eSATA functionality, but NCQ is a server-related technology, handling multiple requests for disk access at once. It is a largerly useless technology on a single user workstation, and you won't see any difference in disk usage between AHCI and IDE.

As long as you have the RAID drivers loaded in the OS it will run in AHCI mode.

You do not want RAID drivers loaded, unless you are referring to a chipset that I'm not familiar with. IDE, AHCI, and RAID are completely separate and independent...and all have separate drivers. For example, with Intel chipset boards, AHCI is picked up by Windows 7, and the chipset drivers install the official drivers from Intel. RAID requires an entirely different BIOS settings and driver package form Intel. They are not one in the same.

 

[Mark Phelps]

Don't know what your motherboard allows, but I have a Gigabyte board and did the EDI-to-AHCI switch as follows:
1) BIOS supports setting SATA mode differently for different ports
2) Set AHCI mode for some ports, IDE mode for other (originally, had all ports set to IDE)
3) Changed the SATA cable to connect to the IDE port
4) Booted Win7 -- it automatically installed the AHCI drivers
5) Had to reboot a second time
6) Switched the SATA cable to the AHCI port
7) Rebooted -- works fine.

 

[unifex]

You do not want RAID drivers loaded, unless you are referring to a chipset that I'm not familiar with. IDE, AHCI, and RAID are completely separate and independent...and all have separate drivers. For example, with Intel chipset boards, AHCI is picked up by Windows 7, and the chipset drivers install the official drivers from Intel. RAID requires an entirely different BIOS settings and driver package form Intel. They are not one in the same.

Well, that's the thing for Dell Inspiron - there is no separate setting in the BIOS for AHCI. Only IDE and RAID. But, RAID actually corresponds to AHCI, so by choosing RAID I actually get the AHCI BIOS screen and so on.

As far as the performance, take a look at the screenshots. I used HDTune to measure the read performance of my SSD and the HDD when I run the OS from HDD in IDE mode and also when I run from SSD in AHCI mode. The latter shows slightly better performance. The caveat is that in IDE mode the computer was also doing something else at the time.

 

[DeaconFrost]

Your caveat pretty much throws the comparisons out the window. I can't speak for SSDs, but for HDDs, the differences between IDE and AHCI aren't performance related.

 

[unifex]

Here's the data for IDE setting without anything running. Clearly, for the HDD the load is important, while AHCI vs IDE not so much. For the SSD AHCI provides a bit of a benefit. Also, in the IDE mode the SSD is not used in any way, that's how the PC is setup.

 

[DeaconFrost]

I have very little experience with SSDs, as I had one for a week and then sold it, but I was under the impression that some of them required the ports to be set as AHCI. I can certainly believe that AHCI would lend a benefit to those drives, and it is good to see that AHCI is offering something for SSDs, as I'm in the market for a 120-160 GB model.

 

[GeneO]

I don't think any SSD driver requires AHCI. But I believe it is true, though there still may be some question, that in order to get TRIM support you need AHCI and not IDE. Maybe that is what you are thinking of.

 

[essenbe]

I have a Dell 580S. In BIOS under advanced chipset settings There is a listing for SATA controller. I can set that to AHCI.
I have 2 SSDs and it is not necessary to run them in AHCI, But you will get better performance and Trim with ahci. That is for most SSDs. I have heard that there are some SSDs that will run better in IDE mode.

 

[DeaconFrost]

Maybe that is what you are thinking of.

That very well may be what I'm thinking of.