34 GB of commited memory but no app actually commited that much
Ask Question Asked 3 years, 8 months ago Modified 3 years, 8 months ago Viewed 493 times 3Sometimes I encounter Out of memory errors and Windows Event Viewer shows this (translated):
Resource-Exhaustion-Detector: A lack of virtual memory in the system was successfully detected. The largest amount of virtual memory was allocated to the following programs: 10582573056 bytes were allocated for myapp.exe (12412), 916819968 bytes were allocated for firefox.exe (18240) and 794206208 bytes were allocated for firefox.exe (13724).
myapp.exe allocated 10 GB, Firefox.exe-s allocated totally ~4.5 GB, some other stuff 10x150MB (as I check later in Task Manager), so total commit should be 16 GB but since I receive these lack of memory warning I assume that the real commit is about 34 GB (32 GB of RAM + 2 GB pagefile).
What could be that hidden thing with big commit that is neither shown in Task Manager processes nor reported by Resource-Exhaustion-Detector?
Is cached memory shown in Task Manager counted towards commited? If counted then why isn't it freed when another app tries to allocate for its needs (as I understand cached memory just fills not used RAM and should be immediately freed when that memory is required)?
Here is a screenshot of different time when Task Manager shows 19.3 GB commited but if I sum everything in allocated column in Details tab it's ~14.3 GB, not 19.3.
Update
This is not a duplicate of Resource-Exhaustion-Detector: out of virtual memory, but plenty of RAM available
In that previous question I asked why I receive out of memory when I have free RAM, now I know the answer - because I'm out of commited memory. Now I'm asking why I'm running of commited memory while no app actually commits that much. They are different.
None of these either answer my question because they are about having physical memory free but receiving Out of memory errors, but I'm asking about reasons why I have no free virtual memory:
- Windows says RAM ran out while there is still 4 GB of physical memory available
- Commit charge is 100% full but physical memory is just 60% when using no page file
- Why is my "Committed" memory so much higher than my actual RAM space?
Vlad
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- @Vlad Much better. I've reopened this one for you. – DavidPostill♦ Jan 12, 2020 at 13:21
- When looking at the processes and their memory consumption I would recommend to use Sysinternals Process Explorer instead of the TaskManager and enable all the different memory columns. This tool also has the advantage that it does not suffer from any translation (usually more on obfuscation that a translation). – Robert Jan 12, 2020 at 14:00
- Your pagefile is extremely small. It is normally recommended for it to be the size of the RAM. How are you getting the numbers for the programs? – harrymc Jan 12, 2020 at 14:10
- @harrymc I summed Task Manager's allocated column. Now rechecked with sum of PagedMemorySize in PowerShell and it's 17 GB commited by processes (of 22 GB total commited). – Vlad Jan 12, 2020 at 14:21
- @Vlad - Have you set the size of allow Windows to set the size? – Ramhound Jan 12, 2020 at 14:35
Why is my "Committed" memory so much higher than my actual RAM space?
Ask Question Asked 8 years ago Modified 2 years, 8 months ago Viewed 298k times
I have run two virus scans and neither of them have found anything so far (Malware Bytes and Avira Rescue). During gaming I will get Windows popups saying that my system is low of memory and recommends closing the game. This can also happen while browsing. My computer seems to become sluggish a lot and will hang up often, such as when clicking a link from a messenger program to open in my browser.
I am unsure what is causing this. My memory usage on the processes tab doesn't add up to such a high percentage of my actual memory.
As a side note, is my Disk Usage supposed to spike up to 100% sometimes? Research seems to say so.
Share Improve this question edited Sep 7, 2017 at 12:04
Daniel B
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asked Sep 12, 2015 at 7:40
Ryld
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- 1 post dome details about your hardware. Do you use a Broadcom Wifi device? – magicandre1981 Sep 12, 2015 at 15:55
3 Answers
82"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.
Share Improve this answer edited Jul 18, 2017 at 16:53 answered Sep 16, 2015 at 19:02
Jamie Hanrahan
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- 2 I was about post "@Ryld If you want to learn more about virtual memory read this really good answer from another question"... Then I noticed that the answer I was linking to was also written by you :). I think I have directed 4 or 5 other questions about virtual memory to that answer, thanks for doing such a good in depth answer. – Scott Chamberlain Sep 16, 2015 at 21:09
- 1 How does "committed" show 31.9-30.1=1.8GB free, but Windows reports 3.6GB is free? Chrome stops opening tabs when "committed" runs out but Windows would say there is still 1.8G "Available"? This seems incredibly wrong/inaccurate. – rektide de la faye Jul 9, 2020 at 19:55
- For helping localization on this answer, the "Commit Size" column is named quite different in Spanish as "Tamaño de asignación" ("Assigned Size", no reference wording to memory) – JCM Apr 7, 2022 at 10:57
- What does the value in the committed signify? For example - does it mean that the RAM should be upgraded to that value? – variable May 25, 2022 at 6:15
- @JamieHanrahan from the pic, there is 25.8GB (30.1-4.3) stuff swapped to page files. Why there is still space in RAM (7.9-4.3) GB,but finally some stuff finally moved to page file? – Grace Jul 29 at 15:25
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"
Ian Boyd
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What is your reasoning behind
while only having 16 GB of "RAM"? The image from the questions reads: In use 4.2+Available 3.6=7.8 . So why did you write 16FB? – variable May 7, 2022 at 12:31 - 1 @variable That was a typo. Where i wrote "16 GB" it should read "8 GB". – Ian Boyd May 7, 2022 at 16:38
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!
标签：commited,no,app,RAM,share,memory,sheet,data,se From： https://www.cnblogs.com/ioriwellings/p/17736011.html