ACPI X64-Based PC Definition & Explanation

explaination of ACPI x64 based pc

There’s a lot of discussion going around ACPI X64-Based PC and how it can benefit you. But before we dig into details, it’s better to understand what ACPI really is and how it affects the rest of your system.

What is ACPI X64?

ACPI means “Advanced Configuration and Power Interface” a protocol or standard set by a microprocessor, operating system, firmware, or attached accessories. In general, it is a method used for controlling the power states of a PC and devices attached to it. ACPI is the same feature that triggers sleep mode and other power-related functions on a PC.

The X64 implies that the system is compatible with X86 64 bit extensions.

ACPI X64 Based PC

The ACPI is a protocol or standard that was released back in 1996. Initially, it was integrated into notebooks or laptops to save battery life. Generally, ACPI helps a computer to be more power-efficient while maintaining its performance.

There might be some peripherals connected to your computer that you are not using every time. For example, CD/DVD ROM, USB devices, extra-hard drives, etc. As these devices are connected to your computer, they will use some portion of energy. As a result, a lot of energy is wasted which reduces the battery life of a computer.

So the idea was to build a standard that shuts down the peripherals or firmware that’s not in use. This gave birth to the ACPI standard. The ACPI helps the operating system control the power states of hardware connected to a computer.

G-States of ACPI

ACPI is integrated with G-States or the Global States to control the hardware of a computer. Every state has a specific function assigned to it.

G0Computer Powered-On
G1Computer Sleep Mode
G2Computer Powered Off
G3Computer Un-Plugged
G-States of ACPI

There are some additional states that work under the G1 State and are listed below:

  • S1: Power-on Suspend
  • S2: CPU Turned Off
  • S3: Standby Mode
  • S4: Hibernation

If you want to shut down your computer without pressing the physical button, then such a command is the result of a G-State of ACPI. Without ACPI, it’s difficult for a PC or laptop computer to have better power management.

D-States of ACPI

ACPI standard also supports a number of D-states that control the specific devices attached to your computer.

D0Device Operational
D1Intermediate State
D2Device Off
D-States of ACPI

C-States of ACPI

These are specifically meant for CPUs and they are shown in the table below:

C2Ready but long waiting time
C3+Additional CPU states as per different models of CPU in the market
C-States Table

There are some sub-category states in C-states that are called P-states or Performance States. These states are classified under the C0-States.

  • P0: Max Power/Frequency
  • P1: Lower Power/Frequency

So this is what ACPI is all about, this is an open standard that allows the operating system to perform power management. With the blessings of ACPI, we can now design applications that let us save more energy. With the help of software tweaks, we can make computing more energy-efficient rather than redesigning the hardware.

Updating Your ACPI X64 Based PC Drivers

A good way to make your PC more energy-efficient is by keeping your ACPI X64 Based PC drivers up to date. One of the most reliable of doing this through updating your Windows. Also, updating your network card, Audio, and Video drivers can help in this regard as well.

With the Windows Automatic Update feature, you can easily keep your ACPI X64 drivers up to date. Furthermore, this can also be done manually by heading over to the Driverscape and downloading the drivers to install them later on.

Operating Systems that Support ACPI X64

Microsoft Windows 98 was the first operating system to support ACPI X64. But in the initial stages, there were some bugs that made this protocol not that much effective. However, the later versions of operating systems like Windows Vista, Windows XP, etc showed improved performance. Most versions of Windows use acpi.sys to deal with ACPI events.

In Windows XP, there is an option to disable ACPI by pressing F7 before installing the Windows. However, in the later versions of Windows like Vista, Windows 8, etc, there isn’t any option to disable this protocol.

How ACPI Interacts With the Hardware

ACPI-compliant system communicates with your hardware via Function Fixed Hardware (FFH) Interface, which is a programming model based on ACPI Machine Language (AML) as provided by the OEM.

Bottom Line

We hope you now have enough knowledge of what ACPI X64 is and the role it plays in power management. In simple words, the ACPI X64 is a protocol responsible for giving instructions to your operating system to switch off unused hardware connected to your computer.

  • Robert Milakovic

    Robert, based in Osijek, Croatia, is a co-founder of Incomera, a media company that has launched several entertainment sites including Fiction Horizon, Game Horizon, and Anime Horizon. He's also a co-owner of Computer Zilla, Comic Basics, and Voice Film. Since an early age, he wa...