- Manually clearing memory cache and buffers enables the User to continue to work without rebooting. With Win7 and earlier, the following typically could be used to clear memory cache and buffers%windir% system32 rundll32.exe advapi32.dll,ProcessIdleTasks.
- If you reload the clip on the Movie Clip Editor, the cache will be cleared. Also keep in mind that the amount of memory used for the cache can be managed on the System Preferences (CtrlAltU) -System -Sequencer/Clip Editor -Memory Cache Limit.
Like any other operating system, GNU/Linux has implemented a memory management efficiently and even more than that. But if any process is eating away your memory and you want to clear it, Linux provides a way to flush or clear ram cache.
Personally, I'm using this in my unit test TestInitialize function to clear out the memory cache for each unit test. Otherwise the cache persists across unit tests giving unintended results when trying to compare performance between 2 functions. – Jacob Morrison May 17 '17 at 19:26. Think of a situation when you have scheduled the script to clear ram cache every hour. After every hour the script is executed and it flushes your RAM cache. One day for whatsoever reason, may be more than expected users are online on your website and seeking resource from your server. However, since the costs also play a role and the RAM memory cannot be expanded, many people use a fairly simple trick when the memory reaches its limits - deleting processes that are no longer required from the cache, and creating space for the data that is relevant for your current activities. This increasing your RAM.
How to Clear Cache in Linux?
How Do I Clear My Ram Cache
Every Linux System has three options to clear cache without interrupting any processes or services.
1. Clear PageCache only.
2. Clear dentries and inodes.
3. Clear PageCache, dentries and inodes.
Explanation of above command.
sync will flush the file system buffer. Command Separated by “;” run sequentially. The shell wait for each command to terminate before executing the next command in the sequence. As mentioned in kernel documentation, writing to drop_cache will clean cache without killing any application/service, command echo is doing the job of writing to file.
If you have to clear the disk cache, the first command is safest in enterprise and production as “...echo 1 > ….” will clear the PageCache only. It is not recommended to use third option above “...echo 3 >” in production until you know what you are doing, as it will clear PageCache, dentries and inodes.
Is it a good idea to free Buffer and Cache in Linux that might be used by Linux Kernel?
When you are applying various settings and want to check, if it is actually implemented specially on I/O-extensive benchmark, then you may need to clear buffer cache. You can drop cache as explained above without rebooting the System i.e., no downtime required.
Linux is designed in such a way that it looks into disk cache before looking onto the disk. If it finds the resource in the cache, then the request doesn’t reach the disk. If we clean the cache, the disk cache will be less useful as the OS will look for the resource on the disk.
Moreover it will also slow the system for a few seconds while the cache is cleaned and every resource required by OS is loaded again in the disk-cache.
Now we will be creating a shell script to auto clear RAM cache daily at 2am via a cron scheduler task. Create a shell script clearcache.sh and add the following lines.
Set execute permission on the clearcache.sh file.
Now you may call the script whenever you required to clear ram cache.
Now set a cron to clear RAM cache everyday at 2am. Open crontab for editing.
Append the below line, save and exit to run it at 2am daily.
For more details on how to cron a job you may like to check our article on 11 Cron Scheduling Jobs.
Is it good idea to auto clear RAM cache on production server?
No! it is not. Think of a situation when you have scheduled the script to clear ram cache everyday at 2am. Everyday at 2am the script is executed and it flushes your RAM cache. One day for whatsoever reason, may be more than expected users are online on your website and seeking resource from your server.
At the same time scheduled script run and clears everything in cache. Now all the user are fetching data from disk. It will result in server crash and corrupt the database. So clear ram-cache only when required,and known your foot steps, else you are a Cargo Cult System Administrator.
How to Clear Swap Space in Linux?
If you want to clear Swap space, you may like to run the below command.
Also you may add above command to a cron script above, after understanding all the associated risk.
Now we will be combining both above commands into one single command to make a proper script to clear RAM Cache and Swap Space.
After testing both above command, we will run command “free -h” before and after running the script and will check cache.
“No matter what I do, my Mac is still slow”, an average tech-consultant hears this phrase multiple times a day. Give a person even the most powerful computer, and pretty soon it will be cluttered with apps, extensions, and things that are too much for it to handle. To reverse it, one has to go back and сlean up the mess, removing memory agents one by one. Prepare for a fight — every byte of memory is at stake. So let’s put your Mac on a diet and get it more free RAM to breathe freely.
First, remove desktop clutter. Get a combination of Setapp apps that clear away unneeded desktop files.
Download Declutter Free“Your system has run out of application memory”
How do you know your Mac is low on memory? Floating “rainbow wheels” aside, you may notice your Mac now takes ages to load. You’ll also see many browser applications crashing. You’ll be also thrown warning messages as “Your system has run out of application memory”. To help it, you should first visit the Activity monitor to see memory usage on Mac.
How to check RAM usage on Mac
Go to Applications and type in Activity Monitor in the search bar. This invokes a good old Activity Monitor that should tell how much free memory you’ve got left.
A shortcut to open Activity Monitor:
Press F4 and start typing Activity Monitor in the search bar.
I’ve attached a screenshot from my Mac and as you can see my memory usage almost reached full capacity. Here’s what it all means:
App memory: taken by apps and processes
Wired memory: reserved by apps, can’t be freed up
Compressed: inactive, can be used by other apps
Swap used: memory used by macOS
Cached files: memory you can really use
Notice the colored graph under Memory Pressure. If your graph is all but red and yellow, your Mac is really gasping for fresh memory. It seems counter-intuitive, but “available memory” your Activity Monitor is not that important after all. In fact, it’s a system intended behavior to use all memory resources when available. On the contrary, the Memory Pressure graph is much more telling, so grow a habit to check this graph in the Activity Monitor every now and then.
How to check CPU usage on Mac
Open the CPU tab in Activity Monitor to keep in check CPU-heavy processes. Normally an app would be using 0-4% of CPU. If it takes abnormally more than that, go inside that particular item in the list and press the Quit button.
How to free up memory on Mac
Tip # 1. Remove Login Items to lower Mac memory usage
Login items are programs that load automatically upon Mac startup. Some of them covertly add themselves to the list and this is no good. If you’re looking to free up RAM, they are the first candidates for deletion. Don’t worry, you’re not deleting the app itself, you just stop it from auto-launching every time.
So, to remove Login Items and at the same time reduce your memory usage of your Mac, you need to:
- Open System Preferences and select Users & Groups.
- Click your nickname on the left.
- Select the Login Items tab.
- Check programs you don’t want to load as your Mac starts.
- Press the “–” sign below.
Now, you won’t see these apps pop up the moment you turn on your Mac. Although this method doesn’t require some superpowers of yours, some special Mac optimization and memory cleaner tools may do the job faster and ensure the smooth performance of your Mac. CleanMyMac X is an excellent example of such software. Here’s how to disable Login Items with CleanMyMac X:
- Download it for free and go to the Optimization tab.
- Check Login Items to see the list of apps that get opened when you start your Mac.
- Click Remove.
As you’ve already come to the Optimization module of CleanMyMac, you can also fix hung apps and heavy memory consumers there. In this way, you’ll free up the solid amount of RAM on Mac — 100% free of charge.
Tip # 2. Free up disk space if Mac is low on memory
The available space on your Mac’s drive translates into virtual memory. This comes to save you when you’ve run out of physical RAM. So now your computer relies on your hard drive space to keep your apps going.
The classic geek rule of thumb holds it that you should keep at least 20% of disk space on your startup drive. Not only this potentially reduces your future spending on iCloud storage but it also keeps your Mac speedier.
What to delete to free up space:
- Large unused files, like movies
- Old downloads
- Rarely used applications
- System junk
But here’s a simpler solution to save your time — clean up your drive with CleanMyMac X— the app I’ve mentioned above. Many users recommend it as an excellent way to free up more space because it searches for large & old files, useless system files, Photo junk, mail attachments and shows everything you can safely delete. Interestingly, it finds about 74 GB of junk on an average computer.
Extra trick: How to free up RAM on Mac with CleanMyMac X
Ram Memory Cache Clearing
If you have downloaded CleanMyMac, you may also take advantage of its amazing feature — the ability to free up RAM in a few seconds. Try this next time you see “Your system has run out of application memory” message.
- Go to the Maintenance tab on the left.
- Click Free Up RAM.
- Click Run.
As simple as that!
And you can do it even if you download a free version of the app.
Tip # 3. Clean up your Desktop
This tip always comes at the bottom of instructions and unfairly so as it is quite effective. Without even looking at your Desktop I would assume it’s cluttered with mountains of icons. Thing is, your macOS was designed in a way that it treats every Desktop icon as a little active window. The more icons, the heavier memory usage on Mac. So in order to release available memory resources, it’s recommended to keep your Desktop clean.
You don’t have to do it all by yourself. With apps like Declutter and Spotless, every desktop cleaning session will be scheduled in advance and executed automatically. Your only job is to define the rules on how your files should be organized.
Tip #4. Clear cache files
Another way to free up RAM on Mac is to clear it of cache files. Of course, it won’t save you gigabytes of space, but deleting cache regularly, you can help your Mac run faster and avoid system issues.
So, to remove cache files on your Mac, you need to:
- Open Finder.
- From the Go menu, select Go to Folder.
- Type ~/Library/Caches in the field and press Go.
- In the window that appears, you will see all your cache files.
- Press Command+A to select all files or delete files one by one.
- Enter your user name and password to confirm.
If you find some files still in the folder after you emptied it, maybe you have some windows open on your Mac. Just like that, you can save up some space on your Mac. Don’t forget to empty the bin afterward.
Tip # 5. Tune up Chrome’s Task Manager
Although Google Chrome is not the one to blame for massive memory usage, it can indeed affect your Mac's performance. If you use Chrome as your primary browser, you probably have many windows opened there. Chrome runs a lot of processes to ensure a fast browsing experience for you. So, it uses your RAM for storing your tabs, plugins, and extensions. Look at how many entries Google Chrome has in Activity Monitor:
The question then arises, 'Why does Chrome use so much RAM?' The thing is that each process is responsible for a separate plugin or extension of your browser. For example, when a tab unexpectedly falls, you need to refresh it to continue your work there. If one process were responsible for all tabs and extensions, you would need to restart the whole browser instead. Can you imagine how many times would you do that? That’s the proper answer to why Chrome uses so much RAM.
I’ve been using Chrome for some years only to discover (recently) that Chrome had a task manager of its own. You can use it to force quit memory-heavy processes in the browser. It’s a handy tool because it lets you see how a page weighs on CPU usage on a Mac.
- Go to Chrome settings (dotted icon in the top right corner)
- Click More tools -> Task Manager
To free up even more RAM, close the GPU process. The GPU Process, though helpful in theory to accelerate pages, eats up a considerable amount of memory. Click to end it to free up RAM on your Mac.
Tip # 6. Manage RAM usage with CleanMyMac X menu
CleanMyMac X has another useful and convenient feature for managing your Mac’s performance and memory usage. As you install CleanMyMac X and start it for the first time, it’s icon will appear in your menu bar. Click the icon to open the CleanMyMac X menu. Here you can find updates on the current condition of your Mac and perform quick tweaks to increase your Mac's speed. Whenever you feel like your Mac underperforms, open the CleanMyMac X menu to check how much RAM is available and free it up as well.
Tip # 7. Close Finder windows
Okay, suppose you’re still asking yourself, how do I clear RAM on my MacBook Pro/MacBook Air. The next trick is as magical (you’ll see for yourself) as it is time-saving. It’s no secret that each window in the Finder eats up RAM. But how many open windows are there? Some of them are collapsed or stacked in some blind spot on your screen. This Finder command merges all your windows into one. See how to do it:
How To Clear My Ram Cache
Click on Finder > Window > Merge All Windows
Now you can manage Finder windows more effectively and free up memory on MacBook.
What else you can do to minimize memory usage on Mac
I’ve saved the easiest tips for the end, as long as these ones are self-explanatory.
- Replace AdBlock (very memory-demanding) with a lighter extension
- Keep fewer opened tabs in the browser
- Restart your Mac more often to free up RAM
- Close all hung-up print queues
That was my take on how to make your Mac a bit speedier to use. If you’re looking for more guidance, check simple ways to speed up your Mac.
Frequently Asked Questions
How to check application memory on Mac?
To check RAM usage on your Mac, go to Activity Monitor (Applications > Utilities). In the Memory tab, you will see all the active processes that are using your Mac’s RAM. At the end of the window, there is a Memory Used graph, which indicates how much application memory is used.
How to find out whether your Mac needs more RAM?
Your Mac may be using almost all its RAM, but you don’t need more if it’s using it efficiently. Open Activity Monitor and go to the Memory tab. The Memory Pressure graph shows the current condition of your RAM: green color means your Mac’s using RAM effectively, while yellow is a sign that some application or process is using too much of application memory. The red memory pressure signals that your Mac needs more RAM.
Clear Ram Memory Cache Buffer And Swap Space On Linux
How to quickly free up RAM on your MacBook?
To free up RAM on your Mac, firstly, you should find out what app uses so much of your memory. The memory-heavy programs are listed in Activity Monitor, Memory tab. If there is an app you aren’t using at the moment, click it and press the “X” sign to quit it. This will, in turn, free some of the application memory.