Proper operation of a computer is possible only with coordinated interaction between the hardware and the operating system. Technology is evolving, and lately this has been most noticeable in the field of storage. Modern hard drives and SSD drives are many times faster than those used in computers 5-10 years ago. Used for data transmission SATA interface, through which the drive is connected to the computer. The SATA interface is capable of operating in two modes: IDE and AHCI, and if you have a modern hard drive or SSD, you can speed up your computer by enabling AHCI mode.
What is AHCI mode
As noted above, AHCI is one of the data transfer modes over the SATA interface. As you know, through the SATA interface you can transfer information at speeds from 1.5 to 6 Gigabytes per second. Maximum speed is supported specifically in AHCI mode, which should be used with all modern drives. As for the IDE mode, it is supported in the SATA interface for compatibility with older hard drives.
By default in the operating room Windows system AHCI mode is not always enabled, even if the drives are connected to motherboard via SATA. Because of this, the user loses in computer performance, since the disk speed is limited by software. By setting the AHCI mode, you can increase the speed of the drive by 20-30%, which will affect the overall experience of the computer.
How to find out if AHCI mode is enabled in Windows
Most often, users do not even suspect that it is necessary to enable AHCI mode in order to improve computer performance. At the same time, Windows by default does not always work with HDDs and SSDs, even the most modern ones, in AHCI mode. To check if AHCI mode is enabled in Windows, you need to do the following:
Please note: Also, the absence of devices operating in AHCI mode in the list may be due to the fact that old drives that are not capable of operating in the new mode are connected to the motherboard.
You can also check whether the SATA interface works in AHCI or IDE mode through the BIOS. To do this, you need to restart the computer and press “Del” or F2 during the boot process. The BIOS will launch, where you will need to find the SATA Mode item and see whether the AHCI or IDE option is installed.
Important: If you notice in the BIOS that the SATA interface is set to work in IDE mode, you do not need to switch to AHCI mode, since this will not do any good.
How to enable AHCI mode in Windows
Microsoft began supporting AHCI mode in Windows operating systems with Windows 7. However, you can enable it in Windows XP if you download the necessary drivers on the Internet, made by enthusiasts, and install them. However, it is worth noting that this method does not always give a performance boost, and on Windows XP it is better to abandon the idea of using AHCI mode and work with drives through a standard IDE.
To enable the AHCI mode itself, just set the appropriate setting for SATA in the BIOS. But this must be done before installation. operating system Windows, otherwise when booting the computer will display error 0x0000007B INACCESSABLE_BOOT_DEVICE or go into a permanent reboot state. Therefore, to switch IDE mode to AHCI when installed Windows, you need to make some changes to the registry; below we will look at what actions to perform for each version of the operating system.
How to enable AHCI mode in Windows 10
In the modern Windows 10 operating system, Microsoft did not offer a setting that would enable support for AHCI mode on the fly if the SATA interface previously worked through the IDE. To correctly switch to AHCI mode, you will need to do the following:
After the computer boots, the Windows operating system will prompt you to install the necessary drivers to work with AHCI mode; be sure to do this.
How to enable AHCI mode in Windows 8 and Windows 8.1
To switch the Windows 8 or Windows 8.1 operating system to work with AHCI mode, you need to do some work on the command line. You will need to do the following:
It is worth noting that if the computer runs on an Intel CPU, then you can use standard utility company that allows you to make the necessary settings for switch Windows to work with AHCI. This is done as follows:
Please note: The above method is only suitable for computers with Intel processors, for AMD a similar solution in at the moment No.
How to enable AHCI mode in Windows 7
In the Windows 7 operating system, the method for enabling AHCI mode is close to that used in Windows 10. Here you will also need to make some changes to the registry as follows.
The AHCI mode of operation of SATA hard drives allows you to use NCQ (Native Command Queing), DIPM (Device Initiated Power Management) technology and other features such as hot-swappable SATA drives. IN general outline Enabling AHCI mode allows you to increase the speed of hard drives and SSDs in the system, mainly due to the advantages of NCQ.
In this instruction we will tell you how to enable AHCI mode in Windows 10 after installing the system, if for some reason you reinstall with it previously enabled in the BIOS or UEFI mode AHCI is not possible and the system was installed in IDE mode. I note that for almost everyone modern computers with a preinstalled OS, this mode is already enabled, and the change itself is especially relevant for SSD drives and laptops, since the AHCI mode allows you to increase SSD performance and, at the same time (albeit slightly) reduce energy consumption.
And one more detail: in theory, the described actions can lead to undesirable consequences, such as the inability to start the OS. Therefore, take them on only if you know why you are doing it, know how to get into the BIOS or UEFI, and are ready to correct unforeseen consequences if something happens (for example, by Windows reinstallation 10 from the very beginning in AHCI mode).
You can find out whether AHCI mode is currently enabled by looking at the UEFI or BIOS settings (in the SATA device parameters) or directly in the OS (see screenshot below).
Enable AHCI using Windows 10 Registry Editor.
In order to enable the operation of hard drives or SSDs, we need rights Windows administrator 10 and Registry Editor. To launch the registry, press the Win+R keys on your keyboard and enter regedit.
The next step is to restart your computer and enter UEFI or BIOS. In this case, the first after reboot Windows startup 10 is better spent in safe mode, and therefore we recommend that you enable safe mode in advance using Win + R -
If you have UEFI, in this case we recommend doing this through “Settings” (Win + I) - “Update and Security” - “Recovery” - “Special boot options”. Then go to “Troubleshooting” - “Advanced options” - “UEFI Software Settings”. For systems with BIOS - use the F2 key (usually on laptops) or Delete (on a PC) to enter the BIOS settings.
In UEFI or BIOS, find the choice of drive operating mode in the SATA parameters. Set it to AHCI, then save the settings and restart your computer.
Immediately after the reboot, the OS will begin installing SATA drivers, and upon completion you will be prompted to restart your computer. Do this: AHCI mode in Windows 10 is enabled.
We hope that this material will be useful to you. If you have any questions or additions, write in the comments.
This is the second article on this topic, the first is available at the link:
This article is devoted to enabling the AHCI mode specifically on Windows 8. Yes, the situation with the release of the new operating system has not changed at all and, if you try to enable BIOS mode AHCI without reinstalling the system, Windows will simply refuse to boot. But they didn’t leave this OS completely unchanged: so, if you follow the path in the registry, as on Windows 7, you simply won’t see the folder msahci. And creating this thread will not lead to anything, since in Windows 8, like Windows Server 2012, the name of the driver was changed, and now it is called StorAHCI. Although it has the same functionality and supports the same devices. Hard drives or you can buy an SSD for example.
In Windows 8, two options were found to enable AHCI without reinstalling the system. Let's look at both. The article was originally written for Windows 8, but it turned out that nothing has changed in Windows 10, so it is quite suitable for ten.
I. Enable AHCI standard in Windows 8 and 8.1 using the registry (Works on Windows 10)
Let me remind you that all changes must be made before enabling AHCI in the BIOS.
1) So, first, go to the registry. To do this, use WIN+R and in the window that opens write regedit:
2) “Registry Editor” opens. We need to follow the path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\
3) Look for the ErrorControl key and set its value 0 (zero) (Default " 3 «):
4) Go to the branch StartOverride, there we look for a key with the name “ 0
"and also give it a value 0
(zero): 
5) Close the registry window and restart the computer. During boot, go into the BIOS and enable the AHCI standard. How to do this, read the instructions for your motherboard. Save the settings and exit the BIOS. The next time you boot, the system should boot to the AHCI standard.
This technique does not always work and depends on the configuration of your computer. Microsoft knows about this and in this case recommends using official instructions from Microsoft, available in the knowledge base article KB2751461(http://support.microsoft.com/kb/2751461).
II. Enable AHCI on Windows 8 (works on Windows 10) via booting into Safe Mode
If with the first method the system refuses to boot, do the following:
— disable AHCI;
- do a system restore standard means, usually loads after the first unsuccessful launch;
— we try to enable AHCI through safe mode according to the instructions below.
1) Next we need to run command line on behalf of the administrator. To do this, move the mouse to the lower left corner of the desktop Windows desktop 8 and press the right mouse button in the opened context menu choose "Command Line (Administrator)":
2) In the command line window that opens, write the following and press the Enter button:
Bcdedit /set (current) safeboot minimal
The message “Operation completed successfully” should appear:
3) Restart the system, go into the BIOS and enable AHCI again. After this, the computer should boot into safe mode and install itself. required driver AHCI.
4) Once again, launch the command line as administrator and write there:
Bcdedit /deletevalue (current) safeboot
A record of the success of the operation should also appear.
5) Reboot the computer.
6) The system should boot in AHCI mode. That's all, all that remains is to check that the AHCI controller appears in the device manager.
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On computers that are equipped Intel chipset, it is possible to activate the ACHI mode. This function affects the speed of operation hard drives, information is copied an order of magnitude faster. It also supports various additional features, for example, hot-plugging drives.
Enabling ACHI mode requires some configuration of the computer, otherwise the following consequences may occur:
blue screen with error;
error 0x0000007B INACCESSABLE_BOOT_DEVICE;
Infinite overload may occur.
Enable ACHI in Windows 10 and 7
The easiest way to enable ACHI on Windows is to use the registry. Click Windows key R and launch the registry by entering the word “regedit” in the open field.
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci.
Find the Start parameter and change its value to 0. This can be done simply by clicking on the line.
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\IastorV. Find the same parameter and repeat the procedure completely.
Restart your computer and . In the BIOS, find the Integrated Peripherals section and enable the corresponding controller.
After the next start of the computer, additional drivers will be installed.
Another reboot will be required, after which the mode will be activated.
How to enable ACHI in Windows 8 and 8.1
If you have already enabled ACHI mode and cannot start Windows 8 normally, then you need to return to IDE ATA mode using the BIOS. Then follow these instructions:
Using the WindowsX keyboard shortcut, launch Command Prompt in Administrator mode.
Type bcdedit /set (current) safeboot minimal and press Enter.
Turn off your computer and... Reactivate ACHI mode. This is easy to do by finding the Integrated Peripherals section. Save your settings.
The next time you reboot, your computer device will be activated in safe mode and will independently install the necessary drivers.
You will have to activate the command line again and enter the following sequence of characters: bcdedit /deletevalue (current) safeboot.
After the next reboot, ACHI mode will be active.
To increase the performance of hard drives and SSDs, a special one is used. There's a lot in it useful functions, such as hot disconnection and connection of disks, NCQ and more. In the previous article we looked at how to enable it through the registry in the Windows 10 operating system.
If you are just reinstalling the system, and your BIOS is set to IDE mode, then it is recommended to change it to AHCI. IN modern laptops and on computers, this mode is usually enabled by default; if you use, then using AHCI is only a plus.
Beginners should take this manual very seriously, as unnecessary actions and inattention may result in the system not starting. You must be able to use BIOS and UEFI and be able to fix problems that arise due to your fault.
Before starting the process, you need to find out whether AHCI mode is enabled; you may not need this article right now. You can view it in the BIOS or from Windows.
Go to Device Manager (you can go to it by clicking right click from the Start menu) and open the tab "IDE ATA/ATAPI Controllers", if there is the word AHCI, then the mode is enabled, if IDE, then this mode is used.
So, if AHCI is not active, then let's proceed to enable it.
How to enable AHCI on Windows 10 through the registry?
We launch, to do this, press the hot keys Win + R and enter the command regedit .
As in the previous article, we need to go to the iaStorV section: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorV. On the right side of the window, find the Start option and double-click on it. Change the value to 0, click OK.
In the Services section, find the section iaStorAV open it, there should be a section StartOverride. On the right, find parameter 0, double-click on it and change the value to 0.
We are looking in the section Services chapter storahci, in which the value of the Start parameter is changed to 0.
Finishing touch. There should be a section in the storahci section StartOverride, we change the value of parameter 0 to 0.
You can close the Registry Editor. Restart your computer and enter the BIOS. It’s better, of course, to do it. This can be done if you open the Run window and enter the command msconfig, where go to the “Boot” tab and check the “Safe Mode” checkbox.
When you go to the BIOS you need to find the SATA parameters and select AHCI mode there.
As soon as you save the changes and exit the BIOS, the driver installation will begin. The computer needs to be restarted again.
