Windows 8 64bit say low memory while 4+Gb free

Question

I have windows 8.1 64 bit, 8Gb ram.

My Task Manager shows 49% used ram, but I still get messages like "Windows is low memory, we recomend to close application". It always says that about the application which is not currently active, but uses more memory than other processes (when Firefox is up, it is Firefox, otherwise it's Skype).

So my question is: how to setup threshold or how to force Windows not report about low memory?

Note: even when it has 70+% free it still reports about low memory. Number of application running doesn't metter.

Note 2: it doesn't happen when I start new app. Looks like windows have some memory checker and it pops up that message on regular basis when swap off. It minimizes active apps(games or browser) and show me that weird message.

Solution 1

You are low on virtual memory. This can happen even if you have plenty of free RAM.

It's just like being unable to spend money even if you have plenty of checks left and plenty of money in the bank. You have to have enough money sitting around to cover the checks you've already written or you can't write any more without risking catastrophe should all your checks be cashed at once.

A simple solution is to enlarge the paging file.

A paging file is like a line of credit that Windows can borrow from. Knowing that it can borrow from the paging file should all its checks be cashed at once, it can keep writing checks. Odds are it won't actually use the paging file, but it just needs it to ensure it can keep its promises.

For example, say you have 4GB of RAM. Four applications start up and tell the OS that they might need up to 1GB of RAM (a reservation). The OS says, "fine", and all four applications start. (Would you prefer it not let them run?!)

Say they're using a total of 1GB of RAM now. Then another application starts up and asks for 1GB. What can the OS do? If it says yes to that application, what happens in the very unlikely event that all the applications suddenly use all the memory they asked for? THe OS doesn't have 5GB available, and it can't revoke promises it has already made.

With a page file, of course, it can just write rarely-used pages out to disk and keep all its promises. So it needs the page file to allow another application to run, even if 3GB is free.

With a large paging file, Windows can allow applications to run so long as the actual working set can fit in RAM. Without a paging file at all, Windows cannot allow any applications to run unless it can fit everything in RAM that could possibly be used based on commitments it has already made. That means, for example, that a simple private, writable mapping of a 1GB file makes an entire 1GB of RAM essentially wasted because the application might write to every byte of that file, so that 1GB of RAM can only contain pages that can safely be discarded.

Linux, by the way, allows the operating system to overcommit backing store. The downside of this is that it may need to forcefully kill processes if the OS winds up making promises it cannot keep. This is why Linux has an "OOM kiler" and Windows does not. Most Linux machines have overcommit disabled anyway.

Solution 2

Low memory alert can be turned off by hacking the registry as described below.

However, as registry modifications can destabilize Windows, better first take care of your backups and create a system restore point to which you can go back in case of problems. I have no personal experience with this hack.

Start regedit and position yourself to this key :

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WDI\DiagnosticModules

Export (for backup) and then delete the following sub-keys :

{45DE1EA9-10BC-4f96-9B21-4B6B83DBF476}
{5EE64AFB-398D-4edb-AF71-3B830219ABF7}
{C0F51D84-11B9-4e74-B083-99F11BA2DB0A}

Now reboot.

If you find you have no permissions to delete these registry key, see the article
Take Ownership of a Registry Key in Windows 7.

You should be aware of the fact that if ever you run out of memory without warning, Windows can crash without any prior notice or programs may misbehave strangely.

Also, this advice worked for Windows 7, but was never proved for Windows 8.1.

source

Comments

[soandos]

Shows used RAM, or used memory (i.e. what is the pagefile size, and how much RAM do you actually have?) Also, how much free space do you have?

[arheops]

Sure. Swap not used, Free ram 1.6G,Cache 2.2G,Used 4.2G. Question is not "where my RAM?". Question is "WHY it alt-tab my games/apps to say there are no RAM,while it have free more then 2Gb?" And what i can do with that bad behavour.

[magicandre1981]

have you disabled the pagefile?

[David Schwartz]

@arheops You need a page file. Otherwise, Windows can't use the RAM it has without being able to predict the future, which it can't do.

[arheops]

It have more then 50% of free ram. Question is not "can it or not can". Question is "is there any way to disable notification?". Note, even it notice it never drop any program becuase of no memory.

[David Schwartz]

If you disable the notification, you just won't know that things are seriously broken. You will be unable to launch new programs, and any number of "background" applications that have no way to notify you will start silently failing. You have insufficient backing store, and you need to address it. See my answer.

[arheops]

There are nothing broken. It NEVER stop something on no memory. It just minimize apps and show that message. I am expecting that can be becuase windows 8 was installed on 4Gb ram, now it have 8. But i need know how to fix that. Adding swap is not option.

[Scott Chamberlain]

Why is adding swap not a option? it is the correct way to solve this problem. You mention a SSD, but swap files on SSDs where only really a problem on first generation SSDs from several years ago, it is not a major issue any more.

[arheops]

Becuase it is SSD-based and becuase it is nootbook(ssd with i/o use battery much more,for my model it like 0.5W and 5W). On adding swap it put in swap all after 4Gb. So i still have 4Gb free, 4Gb used and i/o. It looks like windows triing archive goal of having 4Gb+ ram be always free. I want know how to manage that treshhold.

[arheops]

I have tested setup with page file. It result i/o,sorry.

[David Schwartz]

Then ask a question about why it did so, giving as much detail as possible. Maybe something is wrong. Maybe your test methodology is incorrect. But logic says that giving a smart OS more choices should make it work better, not worse. The OS is smart. Giving it a paging file just gives it more choices that it can use or not use based on what's best.

[Scott Chamberlain]

@arheops I strongly feel that your testing method is either inacruate or you are misinterpreting the results. Please put in as a edit to the question how you determined this information with enough detail for us to re-create the process and confirm your results.

[arheops]

My testing method is simple. With swap turned off my ssd in hybirnate state in my usual patern. With swap turned on it can't go hybernate. Maybe os is smart, but i not want it be active SSD due to battery running time - with swap on it is 4 hrs,with swap off it 5.5+. Nootbook is lenove x230 with default windows 8 install from lenovo.

[David Schwartz]

Ahh, a classic XY question. You ask about low vm when your problem is with SSD power management.

[arheops]

No. My problem is message only with condition when swap is off. Why i have turn off swap is other question. Windows ALLOW turn off swap. So not clear why it not work correctly(inform me about something i not want get be informed and no way turn that off) with such condition.

[arheops]

Note, when i have that message popup i still able run memory-hungry application like photoshop over that, and that not result enother popup nor memory problem. It looks like windows just setup to show message when 4Gb reached.

[arheops]

Linux allow set Swappiness. So i need find similar param for windows. I can't agree that 2 of running app requested 8Gb ram,really.

[Scott Chamberlain]

@arheops Look at the numbers for "Commit" in a system with no swap the sum total of the Commit column must be lower than your total ram. The things that report "49% used" usually only report the total of the "Private Working Set" which does not include virtual allocations which would normally go to the swap file. Please give us the total of the "Memory - Commit Size" and compare that number to your total ram. 2 running apps have 8 GB of private working set is very strange, but 2 running apps having 8GB of commit is not that odd.

[arheops]

Okay. If so, how it can run other app like photoshop(1+Gb ram more) withou any issues?

[arheops]

Commit size for firefox is 100mb more then working set size. Peak size is +200Mb. There are only one 32 bit!!! app which can commit 4G. Game itself. But i never spot it have more then 2Gb commit size.

[David Schwartz]

@arheops It can run apps without any issues because it still has plenty of clean pages it can discard. The system will get slower and will eventually fail spectacularly as the number of dirty pages gets to be a higher and higher fraction of the total number of RAM pages available because there is nothing the system can do with anonymous dirty pages but keep them in RAM, even if they haven't been accessed in hours.