And how they make your computer boot faster
HDG Explains — Swapfile.sys, Hiberfil.sys and Pagefile.sys in Windows 8
In earlier versions of Windows, you probably remember the good old swap file. It’s used when physical memory is overloaded and contains objects that normally haven’t been used in a long time. That’s pagefile.sys. Then we had the hibernate option in Windows that allowed you to save the kernel and all of your applications to your hard drive so you could reboot your computer faster than if you were to reboot it from scratch. That’s hiberfile.sys.
In Windows 8/10, things get a bit more complicated. The pagefile.sys is always there, but the hiberfil.sys is only there if you have Fast Startup enabled in Windows. What is Fast Startup? It allows Windows to perform a hybrid shutdown. This is why Windows 8/10 boots so much faster than previous versions of Windows. Check out my previous post explaining what a hybrid shutdown is in Windows 8.
To use the new hybrid shutdown feature, which is enabled by default, hibernation must be enabled in Windows. If hibernation is disabled, you will not have a hiberfil.sys file and you will not be able to use the fast startup option. You can read my post on how to enable hibernation in Windows here.
