In modern computer systems, hard drives are connected in different modes: the desired parameter is selected in the BIOS. The desire to understand the difference between AHCI and IDE may arise when installing a new drive or operating system, which sometimes have strict protocol requirements. It is strongly recommended not to confuse these modes when migrating hard drives from one assembly to another.
AHCI mode(Advanced Host Controller Interface) involves the implementation of the SATA connection protocol - a serial data transfer interface.
IDE mode(Integrated Drive Electronics) allows you to emulate the legacy PATA parallel data interface.
Thus, in one of the modes the connected drive will work as a SATA drive, in the other – as an IDE drive (physically remaining the same SATA). Such a substitution is necessary to ensure maximum compatibility of components and software that does not support the new protocol.
Comparison
Any SATA drive can operate in IDE mode, and users will not have any remorse about this, most will not even notice. Many motherboard manufacturers enable PATA compatibility by default in the BIOS: this will be safer. What happens if you connect, for example, a disk with Windows XP to a system in which the controller runs in AHCI (supports Microsoft operating systems starting with Vista)? A beautiful blue screen with white letters screaming an error. So it’s reasonable to play it safe.
Why then do we need a mode native to the SATA interface? First, the read speed of disk access is faster than PATA, which improves overall system performance. Secondly, two wonderful “buns” are available for SATA: NCQ and “hot plugging” of the drive. This is the main difference between AHCI and IDE: the latter is slower and less functional, although it is compatible with outdated components and software.
Native Command Queuing is a technology that allows you to rebuild the execution queue of read commands received by the hard drive from the system. Moving heads between data tracks takes longer the further away the tracks are from each other. NCQ makes it possible to turn first to those sectors that are nearby, even if the request arrived later. Thus, the operation of reading devices is optimized and speed increases. True, the user can evaluate the increase only at the time of loading the OS or while working with resource-intensive applications, and in other cases the test results indicate it.
If we connect the hard drive to the motherboard and power supply (if necessary) of a running computer, we will immediately notice the difference between AHCI and IDE. In native SATA mode, the new device will be detected by the system, as happens with USB drives, and you can work with it. This is convenient if you need to quickly transfer data or check the performance of someone else's HDD. The PATA interface, including the emulated one, requires a complete shutdown of the computer. In the best case, when manipulating the disk, the system will ignore it, in the worst case, the equipment will cause a serious failure.
Another important point: in IDE mode it is impossible to install operating systems on SSD drives. SSDs require AHCI to be enabled.
It is quite natural that owners of desktop computing systems and laptops strive in one way or another to increase their performance. To solve this problem, some use the so-called overclocking (overclocking) of components, while others make adjustments through the capabilities provided by the developers. When choosing any method, it is important to understand what exactly you want to get and to have a good understanding of the features of the chosen method.
"Bottleneck"
It is known that one of the slowest components of a modern computing system is based on a classical spindle system. Today, SSD analogues have appeared, but they have not yet become widespread due to their too high cost.
Therefore, regular HDDs are installed on almost every computer. The result is that DDR3 memory easily transfers 20,000 MB/s; The internal CPU bus allows you to process ten times more data; and a hard drive with the SATA-3 standard only “accelerates” to a real 100 megabytes per second under ideal conditions. It is no coincidence that it is recommended to use high-performance SSD models, at least for system files. From all of the above, a simple conclusion follows: it is the HDD that slows down the modern system, thereby being a “bottleneck”. And since the user can easily make changes to the way the disk subsystem processes commands, affecting speed to a certain extent, you can often hear the question of which mode is better: AHCI or IDE.
Standards
The interaction of the disk with other components of the computer system occurs through a special control controller. This chip serves as a kind of command translator, converter. Until recently, the only “language” understood by the controller was the IDE protocol.
It originated at the dawn of the computer industry and has been modernized several times. With the advent of high-speed SATA drives, a radical reworking of the protocol was required. This is how it arose to easily cope with the increased data flow (interface), supports the fashionable NCQ command queue and implements the ability to turn off the device “on the fly”. So what is AHCI? IDE with some new features added. Everything is so simple at first glance.
Opportunities and prospects
Since the standards are backward compatible (SATA devices work perfectly using the IDE protocol), the BIOS or its equivalent almost always contains an item that allows you to select the desired mode.
In many cases, this is the only way to ensure normal computer performance. The mode selection function is present only in the software of those motherboards that support SATA. These are all modern systems. However, hybrid solutions can also be attributed here, allowing you to connect both classic IDE devices (PATA, wide connector comb) and SATA (compact connector). So, AHCI or IDE? What's better? To make it easier to understand this, here is a list of “bonuses” that a user receives by activating a more modern mode:
1. via internal electronic circuits “disk controller - board controller” reaches from 1.5 Gb/s (gigabit) for modification SATA-1 to 6 in the third revision. Let us remember that UDMA-6, in which old hard drives can work, provides only 133 Mbit/s.
2. When talking about which is better - AHCI or IDE, one cannot fail to mention support for NCQ technology. Its essence lies in the fact that the hard drive can “interfere” with the command flow queue, rearranging them to improve operating efficiency.
3. Possibility of “hot” replacement of the device, which does not require shutting down the entire system.
4. Parallel access to all disks at once, without using alternate switching.
Here is a very tempting list of possibilities. No wonder the question is: “AHCI or IDE: which is better?” is perhaps one of the most painful. Many computer owners, surprisingly, still believe in the “magic button”.
Theory and practice
So, after all, AHCI or IDE - which is better? From the above list we can conclude that the outdated protocol is significantly inferior to the new one. However, this is not quite true. Let's consider this point in more detail. Yes, indeed, the data transfer speed has increased tenfold, but the magnetic disks in hard drives both rotated at a speed of 7200 revolutions (the most popular solution) and still rotate. Accordingly, no revolutionary breakthroughs occurred in the reading process. The user will not see 6 Gbit transfer in any HDD test. Even 200 Mbit is unattainable! The exception is solid state drives. If there is such a device in the system, then you don’t have to deal with the question: “AHCI or IDE: which is better?”, but immediately activate the updated protocol. However, as we pointed out, due to cost, such drives have not yet become widespread.
Very often in debates about whether AHCI or IDE is better, the main argument in favor of the former is the protocol's ability to support NCQ. Indeed, when several programs are actively accessing the hard drive at once, this function allows you to rearrange the flow of requests in the most optimal way. However, on an average computer, more than two or three programs rarely access the disk at the same time, so it is impossible to talk about a complete lack of acceleration, but it is obtained within the margin of error.
IDE or AHCI - which is better? Windows 7, when the latter mode is activated, supports connecting/disconnecting a SATA device on the go. Quite convenient, especially in server systems where shutdown is undesirable. However, to use “hot swap” it is recommended to use not internal connectors, but SATA modifications routed to the case.
And finally, the protocol allows several hard drives on the bus to work simultaneously, rather than waiting for requests. It is in this case that the potential of NCQ is fully revealed. Not relevant for the average computer.
As a result, it turns out that although the AHCI protocol is more interesting from a technological point of view, nevertheless, the majority of users will receive nothing but moral satisfaction from its inclusion. There are only two exceptions to the general rule: a server system and the use of an SSD.
Nuances of use
Although you can switch modes in the BIOS in a few seconds, there is one important point to consider. It is as follows: if the operating system was installed, for example, with AHCI, then after transferring to IDE, loading may not be possible. This is not a rule, but most often this is how things happen. Therefore, even before installing the distribution, you need to decide which disk subsystem protocol you plan to work with.
AHCI driver packages began to be integrated into the system only with Vista. All previous solutions from Microsoft do not have built-in support, so you need to either use “assemblies” or prepare media with the appropriate driver before installation. Windows 7 works fine with the new standard. Switching SATA from IDE mode to AHCI must be done from the BIOS (Configure SATA item). In very rare cases, changes to the registry may be required.
Switching method
In order to get into the BIOS, immediately after turning on the computer system, you need to press the Delete button (personal computers) or F2 (laptops) several times in a row. Depending on the implementation, the required item may be located in any sections. For example, to activate it, you may need to switch Boot Mode to CSM instead of UEFI, after which Compatible (IDE) and AHCI appear. The item you are looking for may be in the SATA Enhanced section. You need to carefully review the entire existing list. After switching, press ESC and agree to save the changes.
Results
The decision about which protocol to choose depends on several factors. First of all, it depends on the operating system used. From compatibility at the “hardware” level. And of course from the load on the subsystem. The higher it is, the more preferable AHCI is. If we analyze all the reviews, we can say that both protocols work great, without causing any failures when configured correctly. However, it makes more sense to use the updated version. This is, so to speak, a foundation “for the future,” for example, for the purchase of an SSD.
Competent operation of a computer becomes possible in cases where the operating system and hardware interact harmoniously. Technologies are developing, especially in the storage category. Modern SSD drives and hard drives are distinguished by the fact that they work faster than the versions used 5 - 10 years ago.
Data transfer is carried out using the SATA interface; it is through it that the computer is connected to the drive. It is noted that the SATA interface can operate in two modes: AHCI and IDE. If your computer uses an SSD or a modern hard drive, then AHCI mode can significantly speed up the computer. You can find out about ahci in this article.
AHCI as a parameter is one of the modes for transmitting information over the SATA interface. Through this interface it is possible to transfer data at speeds from 1.5 to 6 Gb/s. It is in AHCI mode that maximum speeds are supported, which will be relevant for working with modern drives. If you look at the IDE mode, the SATA interface supports it only for compatibility with older types of hard drives.
In the default settings of the Windows system, AHCI mode is not always enabled, even if the drives are connected via SATA to the motherboard. This significantly reduces the performance of the computer, since the disk speed indicators are limited by software. If you install ahci mode, the speed of the drive can be increased from 20 to 30%. This will become evident from the general sensations from the operation of the computer you are using.
How to determine if AHCI mode is enabled
Often, users do not even know that they need to enable AHCI mode to improve computer performance. Windows by default does not always enable AHCI mode for working with SSDs and HDDs. To check whether AHCI mode is enabled in Windows, you need to perform the following operation:
- Right-click on “Start”. Then a drop-down menu appears where you need to select “Device Manager”.
- Then a list opens with “IDE/ATAPI Controllers” devices.
- Review the list of devices in detail. If there is no ahci mode in the name, then most likely it is disabled in the system.
Another version, according to which there are no devices using AHCI mode in the list, is due to the fact that old-style drives that are not capable of working with the new mode are connected to the motherboard.
There is also a way to check in which mode the SATA interface operates using the BIOS. To do this, you need to restart the computer, and while loading, press “F2” or “Del”. This will launch the BIOS, where you need to go to the SATA Mode menu and find out whether the option is IDE or AHCI.
If you see in the BIOS menu that the SATA interface is connected to work in IDE mode, then you should not switch to AHCI mode. It won't do any good.
Enabling AHCI mode in Windows
In Windows operating systems, support for AHCI mode began with Windows 7. It can also be enabled in Windows XP, but this requires the ahci driver, which is available on the Internet. This driver was created by enthusiasts. This method will not increase performance, so when working with Windows XP it is better to abandon the use of AHCI mode and continue working with drives using a standard IDE.
Enabling ahci mode involves work where you need to set the appropriate settings for SATA in the BIOS. The operation is carried out before installing the operating system, otherwise the computer will display error 0x0000007BINACCESSABLE_BOOT_DEVICE when booting or will be constantly rebooted. To switch from ide to ahci mode on a Windows computer, you need to make certain changes in the registry. Let's look at the steps that need to be performed for individual versions of operating systems.
Enabling AHCI mode in Windows 10
If you are interested in how to enable ahci mode in Windows 10, then it is worth knowing that Microsoft does not offer a setting that allows you to enable support for AHCI mode on the fly if SATA previously worked with IDE. To correctly switch to AHCI mode, you must perform the following steps:
- The Registry Editor starts. To do this, press the “R+Windows” keys on the keyboard. In the window that appears, you need to enter the regedit command.
- Then you need to follow this path in the registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorV.
- In the folder that opens, select Start by double-clicking the left mouse button. In the "Values" menu you need to set it to 0, and then click "OK".
- Then you need to set the Start indicator to 0 in the path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci
- The value 0 for 0 parameters is set in the following sections:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\StartOverride
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorV\StartOverride
- When all the required parameters are set, you need to restart the computer to enter the registry. It sets AHCI mode to ensure work with the SATA interface.
When the Windows operating system boots, you will be prompted to install the drivers required to work with AHCI mode.
Enabling AHCI mode in Windows 8 and 8.1
To enable AHCI mode in Windows 8 and 8.1, you need to perform some operations on the command line. You need to do the following:
- Run command line as administrator. You need to right-click on “Start” and select the appropriate section.
- Then enter and use the following command at the command line:
bcdedit /set (current) safeboot minimal
- Reboot your computer. During startup, open the BIOS, where you need to switch the mode from IDE to AHCI for the SATA interface.
- Reboot the OS and launch the command line. Entering and using the command:
bcdedit /deletevalue (current) safeboot
- Another restart of the computer.
If the computer uses an Intel CPU, then it is possible to use a standard utility from the company. This will allow you to carry out the required actions to switch Windows to work in AHCI mode. This is done like this:
- Download the following files from the official Intel website:
- SetupRST.exe is an executable file that provides configuration.
- f6flpy – driver.
- Then you need to right-click on “Start” and open “Device Manager”. In the list where devices are displayed, select the “Disk devices” menu. Calls up the context menu for the drive where Windows OS is installed. In this menu, select the “Update drivers” option.
- The utility that updates the drivers will start. In it, select the option “Search and install drivers manually.” The downloaded f6flpy driver is then installed.
- The computer is rebooted, and AHCI mode needs to be activated in the BIOS.
- When loading Windows, you need to execute the SetupRST file, which configures the computer.
This method is only relevant for versions of computers running on Intel processors. There are currently no such solutions for AMD processors.
Enabling AHCI mode in Windows 7
You can find out how to enable ahci mode in Windows 7 in the following instructions. The activation method is quite close to the operation with Windows 10. Here it will be necessary to make certain changes in the registry in this way:
- Launch the registry editor using the combination “R+Windows”. Enter the regedit command in the Run menu and click OK.
- Then you need to go to the registry editor along the following path, and Stars is set to 0:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci
- Then the Start parameter, which is located in this folder, is set to 0:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\IastorV
- The computer reboots, and the AHCI mode for the SATA interface is selected in the BIOS.
When the computer boots for the first time, you need to install the entire list of drivers offered by the operating system.
After the computer has entered AHCI mode, errors may occur. They can be fixed by using the free Microsoft Fix it utility. The program is distinguished by the presence of Russian localization, and it is not difficult to understand it.
In most cases, when the above steps are performed, AHCI mode works fine. The system starts working significantly faster. If no results are achieved, then you can reinstall the system when the mode change occurs. It takes time, but the result is guaranteed.
AHCI Video
If you are looking at this article, then most likely you need help in choosing the correct mode for your hard drive, the installation of which can optimize the operation of your computer. Below we will look at what to vote for: ACHI or IDE.
First of all, let's try to understand what AHCI and IDE are.
IDE
The IDE connector is an outdated 40-pin connector that was used to connect disk drives and other devices that support a similar connector. Today this connector is not used on computers, and on older ones it needs to be replaced.
SATA
To understand the main task of ACHI, it is necessary to mention the SATA connector, which replaced IDE. SATA is superior to IDE primarily due to increased speed and .
ACHI
Now we have come to the third point. AHCI is an operating mode for SATA devices that ensures normal operation.
What to choose: IDE or ACHI?
It's simple: choose AHCI. You should choose IDE only if SATA drivers are not built into your OS. Considering that all more or less modern computers support SATA, in fact, by choosing IDE, the computer will emulate it, and this will not lead to any increase in performance.
