Solved How to clear System Cache in Task Manager?

October 16, 2010 at 18:31:24
Specs: Windows XP, Core 2

Ah ha! I have a decent question which I can not seem to find an answer to.

Does anyone know how to clear the System Cache under Physical Memory in the Task Manager? There has to be a command line function, or maybe a hidden setting in the MMC, but I am un-aware of any such function. Does anyone have any guesses?


PowerMac 9600(1 ghz G4)
512mb RAM
50gb SCSI
ATi 9200 PCI

See More: How to clear System Cache in Task Manager?

Report •

✔ Best Answer
December 24, 2010 at 06:30:03

There is no way of clearing the system memory except for these crap memory managers.

If you are looking for a system command to clear memory you wont find one because they do not exist. There is no use for one. It's a non issue.


October 16, 2010 at 19:56:23

Why do you wish to do this?
If it is because you think it is using too much memory and it is depriving applications, then you are mistaken. This is labeled "System Cache" but it is actually much more than that. This will typically contain a great deal of application code and data. Windows will always try to allocate memory where it will the most good, and it does a very good job most of the time. This is very complex and not easily understood.

I don't know of any tool that will specifically do what you want, primarily because it is not a good thing to do. I don't know of a single legitimate reason for doing this. If you were to do this it would impair performance.

Report •

October 16, 2010 at 20:14:55

What exactly are you trying to achieve? Reducing the amount of data in the cache ( even if you can do something in registry to alter the way windows manages it) will only result in much slower system performance.

Goin' Fishin' (Some day)

Report •

October 16, 2010 at 20:24:37


Because this is a system that receives no downtime or reboots, of course windows has very-lousy memory management and over time it creeps up, ie. right now it's at 1.5gb's. Plus when something gets stuck in memory it would be nice to clear it, instead of rebooting a system that's not supposed to be rebooted.

So back on topic, does anyone know how to clear the System Cache in windows?


PowerMac 9600(1 ghz G4)
512mb RAM
50gb SCSI
ATi 9200 PCI

Report •

Related Solutions

October 16, 2010 at 21:40:33

Windows DOES NOT have lousy memory management. It is in fact very good. Some who understand it best have called it brilliant.
Unfortunately many people that do not understand how it works have totally misunderstood what Task Manager is telling them and have reached completely erroneous conclusions. They have then gone on to mislead others.

Microsoft is not blameless in this. But the fault lies not in the memory management system but in the misleading and inconsistent usage of terms in Task Manager and in other utilities. They have also done little to educate people how the system actually works. Much of Microsoft's popular level documentation on the subject is misleading at best.

I am quite certain that there is no utility that does what you want. This is because is is a BAD thing to do. If you find such a utility, do not use it as it will almost certainly impair performance.

A high value for "System Cache" is a good thing, a very good thing.

Nothing is ever "stuck" in the system cache. It is there because that is currently the best use for the memory. Memory management in Windows is highly dynamic with RAM being assigned where it is most needed. The system is vastly more complex than most people imagine. And the principles in use are quite foreign to the understanding of most computer users. And that includes many computer professionals. These principles have been in use in large computer systems since the 1960's and have been the subject of a vast amount of research and development. The basic principles are the same as used in Linux and Mac OSX.

My information comes from "Windows Internals", a Microsoft publication by David Solomon and Mark Russinovich. Both are highly respected Windows experts. Mark has a Ph.D. in computer engineering and is currently working for Microsoft. You won't find a more authoritative source for information on the subject anywhere.

Report •

October 17, 2010 at 19:09:04

< I removed my comments - already covered by others >

Ms Hulot's boat

Report •

October 18, 2010 at 21:51:14

Outlander, perhaps you should adopt a different approach? I use a piece of software called 'Crap Cleaner' to do kinda the same sort of thing SAFELY. It can be set to clear your temp. files and 'index.dat'. That should cover most if not all the things you need to clean up. Get it free @:
It'll speed things up.
Ed in Texas.

Report •

October 18, 2010 at 22:16:21

Well... this is getting off topic.

So does no one know of a way?

Glad you are knowledgeable in windows MM, but honestly, it sucks! Programs are allowed to consume as much ram as they need, and programs get stuck in memory ALL THE TIME. This is cause for a reboot, ie. when Internet Exploder will not re-launch normally and generates an exception error until the system is rebooted, this is bad, not good, a very good example of a static system. Most times XP will function normally for about 7 days of hard use before anomalies start to appear and a reboot is required. This is because of XP's #%$-poor memory management. Unix and Linux are also horrible at managing memory. But everyone has their own opinion.

@ Ed
Yeah CCleaner is nice for cleaning out the registry and such, but it doesn't work for the current issue.


PowerMac 9600(1 ghz G4)
512mb RAM
50gb SCSI
ATi 9200 PCI

Report •

October 19, 2010 at 05:34:42

There are a stack of RAM clearing programs available if you look around (including some free ones).

Unfortunately they then increase the paging activity to the HDD which means the system runs even slower. It seems to me that even if you find what you are looking for it will not help your situation. Maybe the odd reboot is the only way forward.

Ms Hulot's boat

Report •

October 19, 2010 at 09:20:50

There are three type of memory allocation in Windows.

A. Memory Allocated and in use. Mainly the OS kernel and currently active applications.

B. Memory allocated and not in use which is the system cache. Mainly DLLs and data that might be needed again.

C. Memory not allocated and not in use.

Windows attempts to keep B; at a maximum at the expense of C. A. is used a required. That is clever and it works, very well.

Windows got a reputation for having bad memory management from Windows 95/98 because it was a hybrid system trying to manage both 16 bit and 32 bit memory blocks simultaneously. A horrendous task that caused all sorts of problems.

Since Windows XP all those problems have been eliminated and Windows XP memory management is a good as you are going to get. Nothing gets stuck in memory unless a rogue application puts it there. That is beyond the control of the Operation System. If something appears to be stuck in memory it is because the OS has determined that it is better kept there than freeing up the memory. Free memory isn't doing anything and is wasted. Windows will free up cache memory when it is needed and in the respect it does a pretty good job. In that case it will probably get swapped out to virtual memory.

Clearing the cache will have much the same effect as re-booting as the computer will run extremely slowly until such time as the cache fills up again with stuff the Operating System has determined is better in memory than on the hard disk.


Report •

October 19, 2010 at 09:31:06

... perhaps then, another way forward is to try to identify rogue applications that stay in memory. You could then consider alternative applications which might be better written.

RAM clearing programs are essentially what you are asking for but I guarantee you would regret going for them. None of them, to my knowledge, are in any way selective and therefore cause the machine to get slower and slower.

Ms Hulot's boat

Report •

October 19, 2010 at 09:37:59

I knew I had spelt rogue wrong but just could not work out the correct spelling.


Report •

October 19, 2010 at 09:42:28

Never mind the spelling StuartS. What you said makes very good sense and that's what matters. It is necessary to properly understand the situation rather than attempting to embark on a fix based on misconception.

Ms Hulot's boat

Report •

October 19, 2010 at 11:02:35

I would add that there is never ever memory not allocated by the OS. The only memory not allocated is ram beyond what the OS can address.

The question is based on misinformation and demonstates a lack of understanding of memory management. As such it can not be answered.

I would be like wanting to clean the gas tank while running the engine.

To say OS memory management is terrible does not differenciate between OS memory management and application memory management. The OS can not correct bad application programming but it can keep it from affecting the rest of the system.

"Plus when something gets stuck in memory it would be nice to clear it"
I would suggest you do the following;
1. contact the application supplier as to a patch to end memory leaking
2. end the application and restart it.
3. if 2 fails locate the apps PID in task manager and end task on it.

Report •

December 24, 2010 at 06:13:45

till now no one has given the exact way to clear the system cache in the physical memory..

he's right we don't have to restart the system and even if we restart the system all the files that are loading will take the system cache...

can anyone tell me the exact way to clear that..

i dont want any explanations i know the purpose of it jus give me the resolution for this issue

Report •

December 24, 2010 at 06:30:03
✔ Best Answer

There is no way of clearing the system memory except for these crap memory managers.

If you are looking for a system command to clear memory you wont find one because they do not exist. There is no use for one. It's a non issue.


Report •

December 24, 2010 at 09:18:12

If you use a memory manager it will clear the RAM but then increase the paging time to the HD. This results in no improvement whatsoever, usually making things worse. StuartS said it all in #15.

We all live on a ball.

Report •

March 12, 2011 at 13:28:08

Hey guys, how many times have you had your XP boxes running for more than a week? There are situations when clearing the cache is desirable, although in theory it should not be so. One way to do so would be to write small app to allocate some memory (specified with argument or in window), and use one or more instances of it to allocate as much as possible (RAM size + page file size - system usage) forcing all caches to be dropped. When apps are closed, memory is free again.It works like a charm ;)

Report •

March 27, 2011 at 21:44:37

Bad analogy in #13 with trying to clean the gas tank while the engine is running, because we are talking about flow of information, not flow of fuel. A better analogy could be a person getting electric shock therapy. You could in theory induce a memory into a brain using electricity, you could also erase memory using the same thing. Clearing a persons memory may not improve the persons' performance (like clearing a cache doesn't necessarily improve a computers'), but if a rogue memory is causing an underlying problem, it may be good to remove the memory instead of repressing it.
There is a way in Linux to simulate a reboot that would clear rogue memory leaking programs from the cache, I haven't found any particular way to do this in Windows. The people who know the problems and possible fixes for these situations aren't able to give you this support because Windows is a closed source proprietary software, end of discussion. These people can only tell you so much, and they themselves can only do so much without breaching infringement.
Memory management is not the same across operating system platforms as some here suggest, only the theory is the same (see #9). The way these systems actually allocate is completely different. Take android for instance, memory management/allocation is based primarily on the amount of times the system has called a particular program in recent time. The more times a person uses an application, this application gets allocated more memory so to start promptly and run smoothly. All programs under android are actually not turned off, they are just simply in idle. Whereas Windows and other like operating systems, all programs are not actually on until the user (or system) calls it to run. The system then allocates based on what the program needs to run, with the preferred performance wanted, and which program is being actively used.
To address the IE statements above, Internet browsers (like most programs) weren't built to idle for weeks. Browsers are simply built for trafficking through information on the internet or on your physical system for short periods like a day or two at the most with multiple restarts of the application. Windows doesn't know certain applications and their mistakes, and cannot simply choose to close off allocation to these programs based on how well they were built.
If we lived in a perfect world, all programs would know how much memory it needs, attempt to grab that memory, and hold on to that exact amount without giving up or taking away any memory to or from another. Also in this perfect world, the operating system would be smart enough to not allocate unnecessary memory to a rogue application. It could maintain its' performance by attempting to patch leaks that these rogue applications may have, be able to utilize a standby RAM or cache to perform these tasks without interrupting memory flow to all other programs, cut off flow to rogue applications, or possibly terminate/restart them. But, we don't live there.
My suggestion, develop a 'simulated' reboot type of program and that may solve these unwanted 'real' reboots, since Windows doesn't come with maintenance tools that cover 100% of the system. The type of tools given to fix and maintain Windows is kind of like only giving janitors just a broom and a screw driver.
Back to that analogy of shock therapy, a brain can confuse itself to a point of a coma, a full blown system restart might be the only way to bring it out of that coma. The brain is just a very sophisticated computer so, your computer will have those same moments of coma like states. Heed my warning and regularly restart.

Report •

March 27, 2011 at 22:39:55

As for a memory leak clearing, there is a cmd for that in the terminal.
CLEARMEM_______________Clear memory leaks
if you say help in the terminal it will list most (if not all) of the possible commands that can be given to the system. Sometimes you will get messages that say
'clearmem' is not recognized as an internal or external command, operable program or batch file.
In this case you may not have the right path set for the utility. The steps to change this are all at the following URL:Helpdesk Geek
Otherwise, you may not have that utility. You can get these and other useful utilities from Microsoft. They are usually for servers and workstations, good luck.
Here is the URL:Microsoft Downloads

Report •

March 28, 2011 at 03:44:24


The function of clearmem is widely misunderstood. It will not help this poster. For an explanation see "clearmem" in this (under Optimization Myths):

"Process Idle Tasks" does some housekeeping (on prefetch etc) but runs automatically anyway when you are not interacting with your computer. There is no evidence that it will address the posters issue.

As already stated, the only real answer is to determine which programs have memory leak problems and replace them with better alternatives.

Please come back and let us know how you got on.

Report •

March 28, 2011 at 07:23:10

Clearmem was designed as a programmers tool, not as a performance enhancement. It has been widely misrepresented as such in many website articles by authors who have no understanding of how a modern OS manages memory. It is not useful to non-programmers.

"Process Idle Tasks" is also of limited usefulness. By default XP does a number of housekeeping tasks during idle time when they will not interfere with other activities. The command in question forces these tasks to run immediately, regardless of system activity. This might be useful when benchmarking to produce consistent results. It may also be useful on laptops that may never be in an idle state long enough for these idle tasks to run. The article linked to by Derek contains more information.

Memory management in XP is very good. With the limited resources available it is about as good as can be achieved. We must remember that XP was designed to run on what is now 10 year old hardware and with as little as 64 MB of RAM. This precluded many of the advanced memory management techniques currently found in Windows 7. It is a credit to the designers that they could create an OS that could run on 64 MB of RAM and take advantage of 4 GB (3 GB available).

And once again, there is no need or benefit in clearing the system cache. The desire to do this is based on a misunderstanding of how memory management works in a modern OS.

Report •

May 1, 2011 at 19:12:56

If clearing the memory is not the answer then is there any good way to figure out which programs are using up memory so you can get rid of them and let the programs you want to use run?

Report •

May 2, 2011 at 02:44:34

Task manager will give you all the information you need.


Report •

May 10, 2011 at 12:47:20

Limiting the System Cache is sometimes beneficial! Specially on 64 bit version of Windows. So if you don't have an answer please stop spreading bs.

If you want to reset the cache size use SysInternals CacheSet.

By-the-way I'm not sure if the System Cache info in Task manager is accurate or what does it exactly count. SysInternals Process Explorer displays differente value (equal to Performance monitor Memory\Cache Bytes counter) for System Cache.

More info about memory management and system cache:
Microsoft Windows Dynamic Cache Service

High System Cache usage with high Disk Read I/O on Windows x64

Too Much Cache

You may experience a decrease in overall system performance when you are copying files that are larger than approximately 500 MB in Windows Server 2003 SP1 or in Windows Server 2003 SP2

Things to consider before you enable System cache mode in Windows XP

(Maximize data throughput for network applications)

Report •

May 10, 2011 at 13:46:14

When a poster doesn't say whether it's 32 or 64 bit then most folk will assume 32 bit. My experience "on 32 bit" is that there is no noticeable improvement after tweaking these areas. At best there is no change, at worst the performance deteriorates.

Anyhow, the poster has not been back since October 2010 so I doubt if he will come back again now.

Please come back and let us know the outcome.

Report •

June 8, 2011 at 17:52:41

I am having similar issues as the original poster, but after reading this thread I see that I, too, was looking for a solution in the wrong place.

I am running Adobe Premiere Elements 9 and when I have a large file the program says that my system resources are low and then freezes.

I am running Win 7, 32. My task manager says 3326 Total; 1225 Cached; 2556 Available; 1320 Free. When I try to run Premiere, the free goes to 0 and freezes. What can I do? I can't get my completed, ready-to-burn file to open again.

Report •

June 9, 2011 at 10:19:47


Start a new post of your own. This one started in October so few people will come back to it as it will be way down the list.

Please do not post then vanish - let us know the outcome

Report •

Ask Question