Raspberry Pi: Get information about the RAM

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]