| # zx_system_get_physmem | 
 |  | 
 | ## NAME | 
 |  | 
 | system_get_physmem - get amount of physical memory on the system | 
 |  | 
 | ## SYNOPSIS | 
 |  | 
 | ``` | 
 | #include <zircon/syscalls.h> | 
 |  | 
 | size_t zx_system_get_physmem(void); | 
 | ``` | 
 |  | 
 | ## DESCRIPTION | 
 |  | 
 | **system_get_physmem**() returns the total size of physical memory on | 
 | the machine, in bytes. | 
 |  | 
 | ## RIGHTS | 
 |  | 
 | TODO(ZX-2399) | 
 |  | 
 | ## RETURN VALUE | 
 |  | 
 | **system_get_physmem**() returns a number in bytes. | 
 |  | 
 | ## ERRORS | 
 |  | 
 | **system_get_physmem**() cannot fail. | 
 |  | 
 | ## NOTES | 
 |  | 
 | Currently the total size of physical memory cannot change during a run of | 
 | the system, only at boot time.  This might change in the future. | 
 |  | 
 | ## SEE ALSO | 
 | [system_get_num_cpus](system_get_num_cpus.md). |