How to Use the macOS hostinfo Command to Display System Hardware Summaries

When assessing a Mac for software compatibility, troubleshooting a server, or generating a quick hardware inventory, administrators often need to know the core specifications of the machine. While the graphical “About This Mac” menu provides basic details, it is useless if you are accessing a remote Mac via SSH. To quickly pull a concise summary of the system’s kernel, processor count, and physical memory directly from the terminal, macOS provides the built-in hostinfo command.

Why Use the hostinfo Command?

The hostinfo command interacts directly with the Mach kernel to retrieve fundamental system properties. Unlike the massive, overwhelming output of system_profiler, hostinfo delivers a highly readable, lightweight summary. It instantly reveals the exact kernel version, the number of physical and logical processors, and the total amount of installed RAM without requiring you to sift through pages of irrelevant hardware data.

Step 1: Execute the Basic Command

Running the command is incredibly straightforward and does not require root privileges.

1. Open the macOS Terminal application.
2. Type the following command and press Enter:

hostinfo

The terminal will instantly print a short block of text. You will see the Mach kernel version, the processor type, and the amount of physical memory available.

Step 2: Interpret the Processor Data

The output provides crucial details about your CPU configuration.

• Physical processors: This number represents the actual, physical CPU cores present on the silicon chip.
• Logical processors: This number represents the total number of processing threads. If your Mac supports hyper-threading (common on Intel processors), this number will be double the physical processor count. On Apple Silicon (M1/M2/M3), physical and logical counts usually match.

Step 3: Check Maximum Supported Processors

The command also displays the “Maximum” processor limits. This is a hardcoded limit within the macOS kernel, indicating the absolute maximum number of processors the operating system architecture is currently compiled to support, regardless of what is physically installed on the logic board.

Step 4: Use it in Automated Scripts

Because the output is short and predictable, hostinfo is frequently used in bash scripts to dynamically check system requirements.

1. For example, you can pipe the output into grep to extract just the RAM:

hostinfo | grep "memory available"

This allows a deployment script to verify that a machine has at least 16GB of RAM before attempting to install a heavy application like Final Cut Pro.

By using the hostinfo command, macOS administrators can instantly identify the core hardware capabilities of any local or remote machine without wading through complex system logs.