views:

507

answers:

2

In Vista Task Manager, I understand the available page file is listed like this:
Page File inUse M / available M
In XP it's listed as the Commit Charge Limit.

I had thought that:
Available Virtual Memory = Physical Memory Total + Sum of Page Files

But on my machine I've got Physical Memory = 2038M, Page Files = 4096M, Page File Available = 6051. There's 83M unaccounted for here. What's that used for. I thought it might be something to do with the Kernel memory, but the number doesn't seem to match up?

Info I've found so far:

A: 

Shared memory used by the GPU?

Petesh
Not really. If the GPU is using shared memory for framebuffers and similar basic stuff, it is not reported as available system memory at all.If, on the other hand, you mean the memory shared like AGP, such memory stays a part of the system address space, GPU only gets additional access to it.
Suma
+1  A: 

I think you are correct in your guess it has to do something with the kernel - the kernel memory needs some physical backup as well.

However I have to admit that when trying to verify try, the numbers still do not match well and there is a significant amount of memory not accounted for by this.

I have:

Available Virtual Memory = 4 033 552 KB

Physical Memory Total = 2 096 148 KB

Sum of Page Files = 2048 MB

Kernel Non-Paged Memory = 28 264 KB

Kernel Paged Memory = 63 668 KB

Suma