Date: 2010apr30 OS: Windows Q. How do I enable the Low Fragmentation Heap (LFH) policy for the main heap? A. Use _get_heap_handle() to get the heap handle then call HeapSetInformation(). You could use this to turn off the LFN if it doesn't suit your application. Here's an example from MSDN:

// crt_get_heap_handle.cpp // compile with: /MT #include <windows.h> #include <malloc.h> #include <stdio.h> int main(void) { intptr_t hCrtHeap = _get_heap_handle(); ULONG ulEnableLFH = 2; if (HeapSetInformation((PVOID)hCrtHeap, HeapCompatibilityInformation, &ulEnableLFH, sizeof(ulEnableLFH))) { puts("Enabling Low Fragmentation Heap succeeded"); } else { puts("Enabling Low Fragmentation Heap failed"); } return 0; }