What is PF Usages under Task Manager

I had been asked following by one of the DBA about PF Usages under task manager.

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The reason I am asking..is that the PK usage on one of my boxes is 29 gig..but when I look at what was allocated ..it was on the c drive with 2 gig allocated..so I am confused.

Can you please shed some light?

I was sure what “PF Usage” shows here is some kind of aggregate value so I “googled” for it and found the following explanation on one of the forum

Per Windows Internals Chapter 7: Memory Management -> Page Fault Handling:

Note that the Mem Usage bar (called PF Usage in Windows XP and Windows Server 2003) is actually the system commit total. This number represents potential page file usage, not actual page file usage. It is how much page file space would be used if all the private committed virtual memory in the system had to be paged out all at once.

This makes lots of sense to me and my wild guess was correct.