64-bit versions of Windows and Windows Server support more physical memory (RAM) than 32-bit versions support. However, the reason to configure or increase page file size has not changed. It has always been about supporting a system crash dump, if it is necessary, or extending the system commit limit, if it is necessary. For example, when a lot of physical memory is installed, a page file might not be required to back the system commit charge during peak usage. The available physical memory alone might be large enough to do this. However, a page file or a dedicated dump file might still be required to back a system crash dump.

KB2860880 talks about the appropriate page file size for 64-bit versions of Windows.

Speaking of Page File, you might want to check out some of these links, maybe:

  1. Hiberfil.sys, Pagefile.sys & the New Swapfile.sys file in Windows 8
  2. How to clear the Windows Page File at Shutdown
  3. MemInfo - A Real-time Memory & Page file Usage Monitor
  4. How to defrag MFT, Page File, Registry, System Files in Windows.