Why is my "Committed" memory so much higher than my actual RAM space?

Solution 1:

"Why is my “Committed” memory so much higher than my actual RAM space?" Because "committed" is mostly process-private virtual address space, and some of this can be in RAM and some in the pagefile.

And some might not occupy any storage at all! That's if it's been allocated but never accessed, hence not "faulted in", yet. But it still counts against the "commit limit" because if it's it accessed in the future, it will occupy storage then. And that's too late for the system to say "sorry, we're all out of room."

The whole point of virtual memory is that it can be much larger than physical (RAM), no?

btw... you appear to have a pagefile of about 24 GB, since you have 8 GB RAM and the commit limit is 32 GB. So your "committed" could be as high as 32 GB. (And at the moment it almost is that high, so reducing or eliminating the pagefile would be a bad idea.)

Whereas RAM used is just that. So, of course, RAM used + pagefile used can be larger than RAM used.

Part of the whole point of virtual memory, after all, is that you can have more virtual memory in use than you have physical memory (RAM).

If you want to find out what's using committed memory you need to look at Task Manager's "Details" tab and enable the "Commit size" column.

Nor will the total of the "Commit size" columns add up to the "commit charge" (30.1 GB on your machine), because other things contribute to commit charge: Nonpaged and paged pool and some more "subtle" mechanisms like copy-on-write sections, pagefile-backed sections, AWE mappings... but these are usually small compared to process-private v.a.s.)

On that tab, the "Memory (Private working set)" column corresponds to what the "Processes" tab shows for "Memory". This is the RAM currently assigned to each process for its committed virtual address space. The remainder will be in the pagefile. But, again, processes have other types of address space, mostly of the sort called "mapped", and some fraction of that will be in RAM as well. There are other system-wide things created by the OS, not specific to any process, that use up RAM too.

In short the "Processes" tab's "Memory" column is not supposed to add up to the total RAM being used. It only shows how much of the total usage is being used privately by each process.

Solution 2:

Windows uses a pagefile, which is like RAM, but stored in your hard drive. It's much slower, but it's useful when you need to use more memory than you have in your computer. Windows stores parts of memory that have not been used for a while in the page file when it needs to store more memory but doesn't have any space in the RAM to store it.

Committed memory is the memory you have in your computer plus the page file. It looks like sometimes programs use too much memory and made windows store some things in the pagefile. The pagefile wasn't big enough to fit all the memory windows was storing in it, so it had to increase its size. It kept increasing its size, until it reached its limit. Now Windows can't further increase the pagefile, which means it can't store any extra memory, so its only option is to tell you to close a few programs to reduce memory usage. The reason your computer is slow is because it needs to load stuff from the pagefile, which is much slower than loading directly from RAM and makes disk usage really high, as the pagefile is stored in the hard drive.

You should not have as many programs open as you do and make sure that your computer has enough memory for the games you're playing and the programs you use. I hope this helps!

Solution 3:

The easy way to think about it is rewind back to 1995.

A high-end PC would have 8 MB of RAM (yes, megabytes). And yet on Windows NT (which became Windows 2000, which became Windows XP) your application's would think that they had access to 2 GB of memory - a number so large it boggles the mind.

And your application could do it:

it could allocate 2 GB of memory
while the actual PC only has 8 MB of RAM

How could that possibly work? How could my program be actively using 2 GB of memory, when the PC only has 8 MB of RAM? Where is all this stuff going? It's obviously not going into the RAM chips.

The answer is virtual memory

Applications allocate memory in 4 KB chunks called pages. If all the pages in RAM are full:

Windows will pick some page in RAM that is rarely used
save a copy of that 4 KB page to a page file
and then give that newly available page to your application

And what if the program who was using that page needs it?

then Windows will detect that your application is trying to access a page that was "swapped" out to the page file
free up some other page in RAM
fill the contents of the newly available page with the values saved on the hard disk

Your application can then access the page as though nothing happened.

Same is true today

you can have "committed" 31 GB of "memory"
while only having 16 GB of "RAM"