It is only natural that owners of desktop computing systems and laptops seek in one way or another to increase their productivity. To solve this problem, some use the so-called overclocking (overclocking) of components, while others use the settings provided by the developers. When choosing any method, it is important to understand what exactly needs to be obtained, and to be well versed in the features of the selected method.
"Bottleneck"
It is known that one of the slowest components of a modern computing system is a hard disk based on a classic spindle system. SSD counterparts have appeared today, but they have not yet received wide distribution due to too high a cost.
Therefore, conventional HDDs are installed on almost every computer. As a result, it turns out that the standard DDR3 memory easily transfers 20,000 Mb / s; the internal bus of the central processor allows to process ten times more data; and a SATA-3 standard hard drive “accelerates” to only 100 megabytes per second under ideal conditions. It is no accident that it is recommended to use productive SSD models at least for system files. From the foregoing, a simple conclusion follows: it is the HDD that slows down the modern system, thus being the “bottleneck”. And since the user can easily make changes to the way the disk subsystem processes commands, to a certain extent affecting the speed, one often hears the question of which mode is better: AHCI or IDE.
Standards
The disk interacts with other components of the computer system 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 arose at the dawn of the computer industry and was modernized several times. With the advent of high-speed SATA disks, a radical redesign of the protocol was required. And so
AHCI came about
. Advanced Host Controller Interface easily copes with increased data flow (interface), supports the fashionable NCQ command queue and implements the ability to disconnect the device on the go. So what is AHCI? An IDE that adds some new features. That's so simple at first glance.
Opportunities and Prospects
Since the standards are backward compatible (the SATA device works perfectly according to the IDE protocol), there is almost always an item in BIOS or its analogue that allows you to select the desired mode.
In many cases, only due to this is it possible to achieve normal computer performance. Function mode selection is present only in the software of those motherboards that provide for working with SATA. These are all modern systems. However, here you can also attribute hybrid solutions that allow you to connect both classic IDE devices (PATA, wide comb 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 the user receives by activating a more modern mode:
1. The data transfer rate on the internal electronic circuits “disk controller - controller board” reaches from 1.5 Gb / s (gigabits) for the modification of SATA-1 to 6 in the third revision. Recall that UDMA-6, which can run old hard drives, provides only 133 Mbps.
2. Speaking about which is better - AHCI or IDE, one cannot but indicate support for NCQ technology. Its essence lies in the fact that the hard drive can "intervene" in the queue of the flow of commands, rebuilding them to increase work efficiency.
3. The ability to "hot" replace the device, which does not require shutting down the entire system.
4. Parallel access to all drives at once, without using alternate switching.
Here is a very tempting list of features. Not surprisingly, the question is: “AHCI or IDE: which is better?” is perhaps one of the most painful. Surprisingly, many computer owners still believe in the magic button.
Theory and practice
So anyway, AHCI or IDE - which is better? From the above list, we can conclude that the obsolete protocol loses significantly to the new one. However, this is not quite true. Consider this point in more detail. Yes, indeed, the data transfer speed has increased tenfold, but the magnetic disks in the hard drives both rotated at a speed of 7200 revolutions (the most popular solution), and rotate. Accordingly, in the process of reading, no revolutionary breakthroughs occurred. In no HDD test, the user will not see 6 Gbps transfer. Even 200 Mbps is unattainable! The exception is solid state drives. If such a device is present in the system, then you can not understand the question: “AHCI or IDE: which is better?”, But immediately activate the updated protocol. However, as we indicated, due to cost, such drives have not yet become mass.
Very often in the debate about which is better - AHCI or IDE, the main argument in favor of the first is the ability of the protocol to support NCQ. Indeed, when several programs are actively accessing the hard drive at once, this function allows you to rebuild the flow of requests in the most optimal way. However, in an average computer, more than two or three programs rarely simultaneously access the disk at the same time, therefore it is impossible to talk about the complete absence of acceleration, but it is obtained within the error range.
IDE or AHCI - which is better? Windows 7, when activating the latter mode, supports connecting / disconnecting a SATA device on the go. Quite convenient, especially in server systems where shutdown is undesirable. Nevertheless, to use the "hot swap", it is recommended to use not the internal connectors, but the SATA modifications brought to the chassis.
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. For an average computer is not relevant.
As a result, it turns out that although the AHCI protocol, from the point of view of technology, is more interesting, nevertheless, from its inclusion the bulk of users will receive nothing but moral satisfaction. There are only two exceptions to the general rule: the server system and the use of SSD.
The nuances of using
Although you can switch modes in BIOS in a few seconds, there is one important point to consider. It consists in the following: if the operating system was installed, for example, with AHCI, then after the transfer to the IDE, downloading may not be possible. This is not the rule, but most often it happens this way. Therefore, before installing the distribution kit, you need to decide which protocol of the disk subsystem you plan to work with.
AHCI driver packages were only integrated 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 should be done from BIOS (Configure SATA item). In very rare cases, registry changes may be required.
Switching method
In order to get into the BIOS, immediately after turning on the computing system, you need to press the Delete button (personal computers) or F2 (laptops) several times in a row. Depending on the implementation, the desired item can be in any sections. For example, to activate it, you may need to transfer Boot Mode to CSM instead of UEFI, after which Compatible (IDE) and AHCI appear in the SATA Controller . The item may be located in the SATA Enhanced section. You need to carefully review the entire existing list. After switching, press ESC and agree to save the changes.
Summary
The decision about which protocol to give preference to depends on several factors. First of all, from the operating system used. From compatibility at the "iron" level. And of course, from the load on the subsystem. The higher it is, the more preferable AHCI. If we analyze all the reviews, then we can say that both protocols work fine, with proper configuration without causing any failures. Nevertheless, it is more advisable to use the updated version. This, so to speak, touched "for the future", for example, for the purchase of SSDs.