AHCI is a compatibility mode for modern hard drives and motherboards with a SATA connector. With help this mode The computer processes data faster. AHCI is usually enabled by default in modern PCs, but in case of OS reinstallation or other problems it may be disabled.

To enable AHCI mode, you need to use not only the BIOS, but also the operating system itself, for example, to enter special teams through "Command line". If you are unable to boot the operating system, it is recommended to create bootable USB flash drive and use the installer to go to "System Restore", where you need to find the activation item "Command line". To call, use this small instruction:

If the flash drive with the installer does not start, then most likely you forgot to prioritize the boot in the BIOS.

Enabling AHCI on Windows 10

It is recommended to initially set the system boot to "Safe Mode" using special commands. You can try to do everything without changing the loading type operating system, but in this case you do it at your own peril and risk. It is also worth noting that this method is also suitable for Windows 8/8.1.

To do correct setting, You need:

After the settings have been made, you can proceed directly to enabling AHCI mode in the BIOS. Use this instruction:

Enabling AHCI in Windows 7

Here the inclusion process will be somewhat more complicated, since this version of the operating system requires changes to be made to the registry.

Use these step-by-step instructions:

Entering ACHI mode is not so difficult, but if you are an inexperienced PC user, then it is better not to do this work without the help of a specialist, as there is a risk that you may reset certain settings in the registry and/or BIOS, which could lead to computer problems.

Before you start searching and thoroughly studying information on how to enable AHCI in Windows 10, it is important to understand what AHCI is, why you need to connect such a technology, and whether all users, regardless of any other circumstances, need to subject their PC to such manipulations.

AHCI allows reorganization disk space to improve productivity

Don’t be lazy and read a little theoretical information regarding the appearance in computer environment such a new regime as AHCI.

The specified theoretical knowledge will allow you to correctly make a responsible decision related to enabling this mode on your personal computer.

Focus of new technologies

If you are a prominent representative of PC users who cannot imagine performing work tasks without computer equipment, if you are trying to find time in the evening to “wander” the World Wide Web and get acquainted with the latest news, play cool games, you have certainly heard a lot about that over the past years, developers have focused their efforts on upgrading disk space.

AHCI mode allows you to increase hardware performance

Over time, the hard drive has grown in size, so it was very important to find ways to increase the performance of the disk subsystem.

Only after he appeared new interface and the SATA standard, the user was offered three unique technologies.

The first “Hot Plug” technology allows the PC user to instantly perform actions with the drive, including turning it off without turning off the electronic computer itself.

Yes, this technology is only useful to those who have several hard drives installed on their computer. New technology significantly saves time on performing these tasks.

The second technology “NCQ” is responsible for the order of execution of service tasks. It is this that helps increase the performance of hard drives. This technology also speeds up SSD, which also helps to quickly solve problems associated with an incredibly huge queue of incoming commands.

The third technology “TRIM” is focused only on modern SSD drives. It contributes to significant acceleration, as well as an increase in the service life of SSDs.

But specifically AHCI is aimed at using the capabilities of SSD, SATA and HDD. To experience the incredible speed increase, it is important that the SATA controller operates in AHCI mode.

Checking for AHCI

Plunging headlong into a theoretical vacuum, convinced that AHCI mode is important for Windows 10, many will express a desire to enable it as soon as possible.

It is important to understand that the new computer technology, on which Windows 7 or 10 is installed, is already accompanied not only automatic connection mode, but also by automatic installation of drivers. If you still have doubts as to whether the specified mode is supported, whether it is installed on your PC or not, you can use useful tips and find the answer to this question yourself.

Mode checking algorithm

Checking AHCI mode in Windows 7 or 10 is easy. Initially, you need to open the “Device Manager”, you can do this in two ways.

First of all, click on the “Start” menu and go to the “Control Panel” menu. In the window that opens, in the first rows of the general list there will be such an important “Device Manager” for you.

You can also open it by entering the phrase “Device Manager” in the search bar.

In the “Device Manager” that opens, you can easily find the line IDE ATA/ATAPI controllers. Click on it so that this section opens and displays its contents.

If the AHCI mode in Windows 7 or 10 is installed, and the corresponding drivers are installed at the same time, in the sublist that opens you can find something resembling one of the entries:

• Standard AHCI1.0 Serial ATA Controller;
• Intel(R)5 Series6 Port SATA AHCI Controller.

Note that the key in both of these entries is the presence of the word "AHCI" itself. Unfortunately, the absence of this word indicates that this mode is disabled and not installed.

In particular, if the word “IDE” flashes in this line, it means that you can confirm that the desired mode is not installed; you will have to work hard to remove “IDE” and install AHCI.

If you really want to change everything, then direct your efforts to familiarize yourself with how to enable AHCI mode in Windows 7 or 10.

Enabling the mode

If your smart machine already has Windows OS installed, you will have to add important changes into the registry of the system itself. By following the recommendations of experienced users, you will definitely succeed and be crowned with great success.

The main thing is not to make your own fantasy adjustments, especially in cases where you are little familiar with this kind of manipulation.

Mode connection algorithm

First of all, you must understand that the AHCI mode must be enabled before installing the operating system, otherwise the operating system simply will not boot upon a subsequent reboot.

Launch registry editor, you can also type “regedit” in the search bar.

In the registry that opens, you will have to carefully review all available branches to find “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci”.

On the right side open window you will find the “Start” key, which you will have to edit; accordingly, click on the “Modify” parameter.

A new window will open in front of you again, in which you will need to set a numeric parameter. Most often, by default, when the mode is disabled, you will be able to find the number 3 there, and you should change it to 0.

This completes the work with the registry, close all windows and restart your PC.

When the operating system starts, call BIOS. This needs to be done to make some changes to enable AHCI on the motherboard.

It’s not difficult to figure out how to change the BIOS IDE to AHCI. Immediately after loading the BIOS, go to the “Advanced” tab, and then in the list that opens, find the “SATA Configuration” line, click on it. A small window will immediately pop up with only two choices: IDE and AHCI. Select the second option.

If you have done everything as prescribed by the algorithm, then when you start the operating system will detect new equipment and carry out automatic installation drivers.

There are times when the user has to do the opposite, look for ways to disable AHCI in the BIOS.

It’s easy to guess that to implement your plan, you will have to go the same way as described above, only in reverse order. It is advisable to start by switching in the BIOS new mode to the IDE and then make all the changes to the registry. So, you can easily figure out how to disable AHCI even on your own.

So, the desire to enable AHCI mode is justified by the emergence of new successful opportunities and technologies. Produce specified actions If you have patience, attention and the appropriate algorithm, it’s not difficult to figure out how to do it all.

At one time the developers hard drives looked for various ways to improve the performance of the disk subsystem, which remained relatively slow from year to year, and progress in the storage environment consisted mainly of increasing HDD capacity. Gradually, the SATA standard and corresponding versions of this interface appeared, which brought some new technologies.

In fact, there are only two common technologies - “Hot Plug”, that is, hot-swappable drive and “NCQ” (Native Command Queuing), a native (innate) command queue. The first technology is quite simple, it allows you to simply remove drives on the fly without turning off the computer, although for this you still need to use their software shutdown. NCQ was able to add agility hard drives, and even more so, it will be able to do this with SSDs that cope well with “deep queues”.

These, as well as some other options, will work if the drive controller is set to SATA AHCI mode. In turn, AHCI (Advanced Host Controller Interface) is an advanced controller operating system that is only available in this (AHCI) operating mode.

The good news is that all modern platforms support the AHCI mode of operation of the internal SATA controller, and it can be easily selected in the settings of the main EFI or BIOS shell.

The bad news is that if the operating system was installed in normal "IDE" controller mode, it will not boot and will freeze after selecting AHCI and attempting to start. That is, you may need to reinstall the operating system. Moreover, to install Windows XP (which, however, is not recommended for using SSD) you will need to have AHCI drivers in advance, otherwise the OS will simply be impossible to install.

Important: You can enable AHCI support on Windows 7 without reinstalling the OS. To do this, before switching the controller to AHCI mode, you need to go to the registry editor.

Editing a registry setting.

• Call command line(ALT + R) type “regedit”, without quotes, of course;
• Find the registry key “HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci »;
• Find the “Start” option and double-click on it. In the "value" field, enter "0". That's it, the system can be restarted and set to AHCI mode.

So does it make sense to use the AHCI mode of the SATA controller? There is definitely a point. Let's take a quick look at the benefits again:

• Support for hot-swap drives;
• Overall productivity increase from NCQ technology;
• Work for maximum speeds(relevant when using a controller and SSD SATA-600);
• Support for additional commands, such as TRIM.

Yes, the TRIM command will only work on the operating system installed on the drive running in AHCI controller mode. You can learn about the importance and usefulness of this command. So there is no reason to use standard mode controller compatibility with IDE.

I ordered an OCZ SSD and this will be the first one I installed. In preparation for its arrival and installation, I looked at the MSI website to make sure I did everything as well as possible the first time. On their MSI HQ User site for the user faq they note the following:

Typically, many hardware testing sites as well as SSD manufacturers recommend using AHCI mode with SSD drives. However, we've done our own tests here on the forum and we think this is only misleading when the SSD drives are used independently (i.e. not in a RAID array).

AHCI mode, as explained earlier, allows NCQ (Native Command Queue), which is not really required for SSDs as they do not need to be optimized in this way since there is no physical movement of heads or tablets. In many cases this may actually interfere SSD operation and even shorten the lifespan of your SSD.

In many of the responses and referrals here at SU, the inclusion of AHCI has been strongly implied. My goal is to establish maximum performance and maximum service life. This statement from MSI has moved me on a quest with you.

So the question is to use AHCI or not and why?

I have MSI 790FX-GD90, 4 GB random access memory, running windows home premium 64.

EDIT: I should add that if all goes well, I intend to get a second SSD for a RAID setup.

2 Solutions collect form web for “Should AHCI be enabled for SSDs?”

I would enable AHCI because:

• This often improves performance (your SSD may be an exception, but if you run an SSD And HDD, then the hard drive will get some boost).
• He offers additional functions(eg hard drives).
• It's enabled almost everywhere and with an unexpected system in old compatibility mode it throws me for a loop. I understand that this may be a personal matter.

Reasons not to use AHCI:

• You are using Windows XP (now almost 12 years old) and do not want to download additional drivers during installation. (XP does not understand AHCI. You need a driver floppy for this).
• If you have a rare situation where one particular drive is slower with AHCI. In the part you quoted, it simply states that it may actually interfere with performance. Not that it happened and that it matters. So I would test with AHCI enabled and with AHCI disabled.

Note that if you are running Windows 7 (or Linux or BSD), you can change the AHCI mode and IDE compatible mode without reinstalling. You need to enable the service in Windows 7.

I tested my 256G SSD in both IDE and AHCI mode (as SSD test Benchmark). It has a big boost in sequential reads (from 338 MB/s to 488 MB/s), a sharp increase in 64-thread-4k reads (from 22.8 MB/s to 175 MB/s) and 64-threaded-4k -records (From 96 to 179). Sequential writes increase slightly from 255 MB/s to 269 MB/s, and access times don't improve as much, but also increase slightly.

AHCI, how to launch and configure it

Advanced Host Controller Interface (AHCI)- a mechanism used to connect storage devices via the Serial ATA protocol, allowing for advanced features such as built-in command queuing (NCQ) and hot swapping. The most important thing is that if the ANCI mode is enabled, the TRIM mode in the SSD is activated. In addition, without ANCI mode enabled, it is sometimes impossible to update the firmware in an SSD (for example, KINGSTON).

The ACHI operating mode allows you to use it to clean up “garbage” on an SSD.

AHCI is built in Intel chipsets starting with some versions of ICH6 and all chipsets for Core platforms i3/i5/i7. For Core platforms, AHCI was implemented in the following controllers:

PCHM Intel RAID/AHCI Controller Hub
Intel PCH SATA RAID/AHCI Controller Hub
Intel ICH10R/DO SATA RAID/AHCI Controller Hub
Intel ICH10D SATA AHCI Controller Hub
Intel ICH9M-E SATA RAID/AHCI Controller Hub
Intel ICH9M AHCI Controller Hub
Intel 82801IR/IO Controller Hub (ICH9R/DO) - RAID and AHCI
Intel 82801HEM I/O Controller Hub (ICH8M-E) - RAID and AHCI
Intel 82801HBM I/O Controller Hub (ICH8M) - AHCI only
Intel 82801HR/HH/HO I/O Controller Hub (ICH8R /DH/DO) - RAID and AHCI
Intel 631xESB/632xESB I/O Controller Hub - RAID and AHCI
Intel 82801GHM I/O Controller Hub (ICH7MDH) - RAID only
Intel 82801GBM I/O Controller Hub (ICH7M) - AHCI only
Intel 82801GR/GH I/O Controller Hub (ICH7R/DH) - RAID and AHCI
Intel 82801FR I/O Controller Hub (ICH6R) - RAID and AHCI
Intel 82801FBM I/O Controller Hub (ICH6M) - AHCI only

How to enable AHCI mode for an already installed operating system.

Windows XP

To install the driver from installed system Windows XP needs:

This is done as follows.
We go to the device manager and find IDE ATA/ATAPI controllers in the list.
We update drivers for controllers (by default there are 2).
To do this, select Update driver => Do not search. I will choose the right driver myself.
Specify the folder path to installation disk to the motherboard.
Uncheck “Only compatible devices” and select Intel(R) ICH8R/D0/DH SATA AHCI Controller from the list. (this is true for both controllers!!!). If you have ICH10R, then set it for 10R accordingly.

Reboot and enter BIOS.

In the BIOS, enable AHCI mode for the SATA controller and save (or dance with a tambourine with a BIOS hack).

During system startup after POST, you will see the SATA AHCI BIOS initialization screen, a list of channels and devices connected to them will be displayed.

If a new device appears and Windows offers to install drivers automatically, we refuse.

Download the updated driver, run it and observe the driver installation.

In the device manager, in the IDE ATA/ATAPI section, controllers are now only: ICH9R/DO/DH SATA AHCI Controller, secondary and primary IDE, Standard dual-channel PCI IDE controller.

The installation is complete - Windows XP now runs in AHCI mode.

If Windows XP does not pick up the AHCI driver, you will see a BSOD with code 0x0000007b after rebooting.
Disable AHCI mode in BIOS, then the system will boot into operating mode and try again.

In fact for already installed Windows XP connection of AHCI drivers occurs in two stages. The problem is that the Intel driver installer will not work without AHCI mode enabled, and with AHCI mode enabled, Windows XP will not boot.

Therefore two stages:

— manually install drivers for controllers, this allows you to load Windows XP after enabling AHCI

— and after downloading, install the full set of drivers through the installer

IMPORTANT for Windows XP

After switching Windows XP to ACHI mode, it is almost impossible to return to IDE mode; there are a large number of forums on the Internet on this topic.
Why go back from AHCI to IDE at all? In AHCI mode, it is not possible to fix Windows XP in recovery mode ( Windows installation XP over the configured system, running the installation file from Windows environment XP).

What to do? Everything is lost? Reinstall again (and lose all settings) in case of serious problems?

We carefully read what is written in foreign letters for the controller driver = Intel(R) ICH8R/D0/DH SATA AHCI Controller. See the keyword? No, that's not a word AHCI, this is another word - Intel.
Bingo - we remember (or read the description for the motherboard) that we have another controller on the board, usually a JMicron / Marvell, which only works in IDE mode.

Switching system disk there, Windows XP boots perfectly in IDE mode (accordingly, in the BIOS we select boot from this disk), because we did not install any AHCI drivers for this controller. Then we fix Windows XP in recovery mode, return the SATA wire to the main ICH controller and quietly work on.

Windows 7

There is no need to install drivers before switching to the BIOS (as in Windows XP) - otherwise the system will crash with a blue screen.

In a nutshell - or run special utility from MS or in the registry, reset the corresponding keys yourself. After Windows 7 starts, it will understand that the controller mode has changed and will install the correct drivers (or default drivers).

To fix the problem yourself, enable the AHCI driver in the registry before changing the SATA mode boot disk. To do this, follow these steps:

1. Close all Windows programs.
2. Open menu Start, in the window To start searching Type regedit and press Enter.
3. If a window opens Accounts users, press the button Continue.
4. Find and select one of the following registry subkeys (both will need to be changed):

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\IastorV

5. In the right pane, right-click on Start in column Name and select a team Change.
6. In field Meaning enter 0 and click the button OK.
7. On the menu File select team Exit to close Registry Editor.

Summary table for two operating systems (Windows XP and Windows 7)

Experiments.

We look at the hardware configuration in Device Manager.

We see the ICH8 controller (there are two of them), but without a letter index, it is not yet clear whether there is AHCI support, we will check.

If there was ICH8E or ICH8R, then there is definitely ACHI.

Drivers can be downloaded both from the Intel website (we are looking for Intel Matrix Storage Manager) and from the official website of the motherboard manufacturer. For example, the budget motherboard MSI P965 Neo-F V2. The specification and technical support claim that the board does not support AHCI mode. Indeed, the BIOS only has IDE mode and no AHCI option. We will continue experiments, see below about the BIOS hack.

SATAII controller integrated in ICH8- SATA controller has AHCI support

and on the drivers page we see - On-Board SATA AHCI/RAID Drivers(there are even drivers)

We carry out all experiments:

— budget motherboard MSI P965 neo-f V2, SATA 2 (4 Intel ICH8 connectors and 1 MARVELL 88SE6111 connector)

— SSD Kingston 140 GB SATA 3

Experiment 1. There is an option to enable AHCI in the BIOS (we don’t have it)

AHCI mode must be enabled before installing the operating system (for Windows systems 7 and higher everything will be fine; for Windows XP you need a floppy disk with F6 drivers. If there is no disk drive at all, you need to install it in IDE mode or look for a Windows build with already installed drivers ACHI). If you turn it on after installing the OS, it will blue screen BSOD. The system does not know that the controller is now operating in a different mode.

What needs to be done for an already installed system.

Return IDE mode to the BIOS and make adjustments in Windows, then reboot and re-enable AHCI mode in the BIOS.

Experiment 2. Intel controllers support AHCI mode (our controller is on the list), but in the BIOS there is no option to switch to AHCI.

What to do? We will do an (easy) BIOS hack. .

We go into the BIOS. For the controller to work in AHCI mode, you need to do Load Setup Defaults in the BIOS after flashing it - otherwise everything will boot in the same IDE mode. And the main thing is not to go to the Configure SATA as menu - it gets confused by IDE - if you go... Which, by the way, is useful for returning to IDE mode.

Attention!

First, we conduct the last experiment on the presence of AHCI mode in controllers! We do not touch Windows (drivers for AHCI) yet. The folder with AMI BIOS files must be saved on drive C: (it may happen after experiments that only this disk will be available)

If after restarting the BIOS all disks disappear from it (i.e. the BIOS sees only the floppy drive), then you are out of luck; the board really does not support AHCI. If you cannot switch back to IDE mode through the BIOS, you need a previously prepared floppy disk with MS DOS, AFUDOS and original file ROM. Then we boot from the floppy disk into MS DOS and fill in original firmware in the BIOS (and also then do Load Setup Defaults). If you have an additional SATA MARVELL controller on the board, you can switch the Windows drive there and boot. And from under Windows, upload the original firmware.

If all the disks are available, return the IDE, make all the changes in Windows for the drivers (as indicated above) - once again upload the firmware with AHCI - reboot.

Experiment 3. What else is on the motherboard?

Remember the scary message

Adapter 1.

Disks Information: No hard disk is detected!

This is just the Marvell controller reporting its operation and that the disk is not connected to it. The controller is activated from the general AMI BIOS, parameter OnBoard IDE Controller, you have to guess that this is Marvell. Nothing, you guessed it, they called it correctly via ROM Marvell IDE Controller. Yes, if you disable it, the message No hard disk is detected! will not appear again.

In our case, this is Marvell 88SE6111, here it is on the motherboard (1 SATA port and 1 IDE port)

It's in the device manager

We try to turn on our SSD there (the message changes at startup) and boot, see what the speed is like.

Marvell 88SE61хх Adapter. BIOS Version 1.1.0.L64

Adapter 1.

Disks Information:

Disk name Size Speed

Kingston SV300S37A240G 240 Gb SATA II

Yes, not very good. The read speed is higher than HDD, and the write speed is even lower than HDD.

HDD via SATA Intel ICH8	SSD via SATA Intel ICH8	SSD via SATA Marvell 88SE61111 on a standard driver

In general, the Marvell controller can only be used for the optical drive.

By the way, this information can be used to select a motherboard. We can increase the frequency, voltage, change the processor and memory, but we cannot do anything with the built-in SATA-AHCI controller. For example, for SATA II and the same SSD:

Intel ICH10 - 350 Mb/s

Intel Z87 - 530 MB/sec

those. you need to look at the current controller tests and then look for motherboard on a chipset that produced maximum SSD performance.

Experiment 4. PCI-e

Yes, we also have PCI-e v1.0a connectors on the board, let's try to use them

PCI-e x16 for a video card, google, for the PCI-e x4 option (you need a second version of PCI-e) there is an option