In this article we show you various command line commands to retrieve information about the memory on your Raspberry Pi
This was tested on a Raspberry Pi 4.
The command “free” provides information about the working memory:
free
When I ran this I saw this
[codesyntax lang=”bash”]
total used free shared buff/cache available Mem: 1911988 173552 1407280 31544 331156 1621596 Swap: 102396 0 102396
[/codesyntax]
Total: This field shows the total amount of memory and how much is installed on your system.
Used: This column tells how much memory is used currently by running processes. The used memory can be calculated using this formula = total – free – buffer/cache.
Free: This field represents how much memory is free or is not being used by any process.
Shared: This field represents the memory that is being shared by multiple processes.
Buffers: This field shows the amount of memory reserved by the OS kernel. The memory could be allocated further if any application needed memory,
Cached: This field tells the amount of memory that is used to store recent data and files in RAM
Available: This field represents the amount of memory available for starting a new process without memory swapping.
If you want the values in MByte right away you can run this
free -m -t
When I ran this I saw this
[codesyntax lang=”bash”]
total used free shared buff/cache available Mem: 1867 170 1373 30 323 1582 Swap: 99 0 99 Total: 1967 170 1473
[/codesyntax]
Memory usage and swap behavior
Learn more about memory usage and swap behavior
cat /proc/meminfo
When I ran this I saw this
[codesyntax lang=”bash”]
MemTotal: 1911988 kB MemFree: 1406312 kB MemAvailable: 1620988 kB Buffers: 60880 kB Cached: 246708 kB SwapCached: 0 kB Active: 301312 kB Inactive: 137896 kB Active(anon): 131896 kB Inactive(anon): 31268 kB Active(file): 169416 kB Inactive(file): 106628 kB Unevictable: 16 kB Mlocked: 16 kB HighTotal: 1232896 kB HighFree: 842044 kB LowTotal: 679092 kB LowFree: 564268 kB SwapTotal: 102396 kB SwapFree: 102396 kB Dirty: 56 kB Writeback: 0 kB AnonPages: 131684 kB Mapped: 99964 kB Shmem: 31544 kB KReclaimable: 23924 kB Slab: 40044 kB SReclaimable: 23924 kB SUnreclaim: 16120 kB KernelStack: 1736 kB PageTables: 3616 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1058388 kB Committed_AS: 935600 kB VmallocTotal: 245760 kB VmallocUsed: 4972 kB VmallocChunk: 0 kB Percpu: 464 kB CmaTotal: 262144 kB CmaFree: 256028 kB
[/codesyntax]
Distribution of shared memory
The following will display the available RAM for the memory of the processor and the GPU in MB
vcgencmd get_mem arm && vcgencmd get_mem gpu
When I ran this I saw this
[codesyntax lang=”bash”]
arm=948M gpu=76M
[/codesyntax]
