Windows SDK: How to get the amount of physical (RAM) memory?
Q: How to get the amount of physical (RAM) memory?
A: By calling GlobalMemoryStatus or GlobalMemoryStatusEx.
Example
Using GlobalMemoryStatus.
Code:
#include <windows.h>
#include <stdio.h>
DWORD GetTotalPhysicalMemory()
{
MEMORYSTATUS memStatus = {0};
::GlobalMemoryStatus(&memStatus);
return memStatus.dwTotalPhys;
}
int main()
{
const DWORD dwMBFactor = 0x00100000;
DWORD dwTotalPhys = GetTotalPhysicalMemory();
printf("Total physical memory: %u MB", dwTotalPhys / dwMBFactor);
system("pause");
return 0;
}
Example
Usig GlobalMemoryStatusEx
Code:
#include <windows.h>
#include <stdio.h>
DWORDLONG GetTotalPhysicalMemory()
{
MEMORYSTATUSEX memStatusEx = {0};
memStatusEx.dwLength = sizeof(MEMORYSTATUSEX);
BOOL bRet = ::GlobalMemoryStatusEx(&memStatusEx);
return memStatusEx.ullTotalPhys;
}
int main()
{
const DWORD dwMBFactor = 0x00100000;
DWORDLONG dwTotalPhys = GetTotalPhysicalMemory();
printf("Total physical memory: %u MB", dwTotalPhys / dwMBFactor);
system("pause");
return 0;
}
Notes
- GlobalMemoryStatusEx must be preferred because:
- GlobalMemoryStatus function will return the correct amount of physical memory between 2 and 4 GB only if the executable is linked using the /LARGEADDRESSAWARE linker option.
- GlobalMemoryStatus returns -1 (indicates an overflow) on computers with more than 4 GB of memory.
Related links
