How much RAM do I have in Linux?

To find out how much RAM you have installed on your Linux system, you can use command-line tools. The most detailed method, as mentioned in the reference, involves the lshw command.

Using lshw to Check RAM

The most comprehensive way to see the total amount of physical RAM installed, along with details about each memory module, is by using the lshw command.

You need elevated privileges to run this command, so you'll typically use sudo:

sudo lshw -c memory

This command specifically filters the hardware list (lshw) to show only components classified as memory. The output will provide details about your system's memory configuration, including:

• Total size: The cumulative size of all installed RAM.
• Individual banks: Information about each RAM stick (slot) installed, such as its size, type (e.g., DDR4), speed, and manufacturer (if available).

As the reference states, this command will show you "each individual bank of RAM you have installed, as well as the total size for the System Memory."

Example lshw -c memory Output

The exact output varies depending on your hardware, but it generally looks like this:

  *-memory
       description: System Memory
       physical id: a
       logical name: system-memory
       capacity: 32GiB
       *-bank:0
            description: DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
            product: HMA81GU6AFR8N-UH
            vendor: Hynix Semiconductor (Hyundai Electronics)
            physical id: 0
            serial: 00000000
            slot: ChannelA-DIMM0
            size: 8GiB
            width: 64 bits
            clock: 2400MHz (0.4 ns)
       *-bank:1
            description: DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
            product: HMA81GU6AFR8N-UH
            vendor: Hynix Semiconductor (Hyundai Electronics)
            physical id: 1
            serial: 00000000
            slot: ChannelA-DIMM1
            size: 8GiB
            width: 64 bits
            clock: 2400MHz (0.4 ns)
       *-bank:2
            description: DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
            product: HMA81GU6AFR8N-UH
            vendor: Hynix Semiconductor (Hyundai Electronics)
            physical id: 2
            serial: 00000000
            slot: ChannelB-DIMM0
            size: 8GiB
            width: 64 bits
            clock: 2400MHz (0.4 ns)
       *-bank:3
            description: DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
            product: HMA81GU6AFR8N-UH
            vendor: Hynix Semiconductor (Hyundai Electronics)
            physical id: 3
            serial: 00000000
            slot: ChannelB-DIMM1
            size: 8GiB
            width: 64 bits
            clock: 2400MHz (0.4 ns)

In this example, the *-memory section shows a capacity of 32GiB, indicating the total RAM. The *-bank sections detail four 8GiB memory sticks.

Alternative Methods

While lshw provides detailed hardware information, simpler commands can quickly show total and available memory.

Using free

The free command displays the total amount of free and used physical and swap memory in the system. The -h flag makes the output human-readable (e.g., using MB, GB).

free -h

The output includes the total column, which shows your installed RAM.

Using /proc/meminfo

Linux systems expose system information through the /proc filesystem. The meminfo file contains detailed memory statistics.

cat /proc/meminfo

Look for the MemTotal line in the output.

Summary of Commands

Using sudo lshw -c memory is the recommended method from the reference to get a detailed view including individual RAM sticks and the overall total.