oahd-helper High CPU Usage on macOS.

What is oahd-helper?

  • How-To
  • 2 mins read

The oahd-helper process is a part of the macOS operating system, particularly on Macs with the Apple Silicon (M1, M1 Pro, M1 Max, etc.) chips. It is related to the Rosetta 2 translation layer that allows users to run Intel-based applications on ARM architecture.

Here's a summary of the key points regarding oahd-helper:

  • oahd-helper is associated with the Rosetta 2's Ahead-Of-Time (AOT) compilation process. When you first install or run an application designed for Intel chips on an M1 Mac, Rosetta translates this code into a format the ARM architecture can understand. This translation process is CPU-intensive and is what's causing the high CPU usage you're experiencing.
  • The process is usually a one-time event for each app; once the translation is done, the CPU usage should go down. In the question you cited, the user reports that the CPU settles after about 17 minutes.
  • This activity is likely triggered by changes in System Integrity Protection (SIP) mode. When SIP is modified, it might cause the system to re-evaluate or recompile some code, thereby activating the oahd-helper processes.
  • To manage the CPU usage, options include:
    • Allowing the process to complete without interruption, especially if it's a one-time compilation.
    • Deleting Intel-based code from the system to reduce the volume of work oahd-helper must perform.
    • Managing the frequency of actions that trigger this process, such as changing SIP mode.
    • Using third-party apps like App Tamer to control the process's CPU usage, allowing you to spread out the work and reduce peak CPU load.

In summary, if you're noticing high CPU usage due to oahd-helper, it's typically because the system is compiling Intel-based applications for use on your Apple Silicon Mac. The process should be temporary, and once it's completed for all your apps, you shouldn't see the same level of CPU consumption from oahd-helper again unless you install new Intel-based applications or change system settings that trigger recompilation.