You still remember the first thing on your mind when you were buying your new MacBook that this Machine will always keep up with your pace and will never slow down on you. That’s exactly what these awesome machines are built to do. But sooner than you think, it starts slowing down. The first thing you need to know is that the performance of your Mac depends a lot on the memory usage on the device. We will talk about some of the ways to learn how to reduce memory usage on Mac and get it to maximum performance again.
Check Your Available Memory Usage on Mac First!
- The last OpenOffice version supporting Mac OS X 10.4 (Tiger), 10.5 (Leopard), 10.6 (Snow Leopard) is OpenOffice 4.0.1. Hardware Requirements ¶ CPU: Intel Processor.
- Free download MemoryFreer MemoryFreer for Mac OS X. MemoryFreer does just what it says - free up memory, especially the inactive memory that occupies the precious RAM on your machine.
- OS X Auditor is a free Mac OS X computer forensics tool. For the Mac Memoryze for the Mac is free memory forensic software that helps incident responders find.
- I have Macbook Pro running Mac OS X Leopard (10.5) with 4GB RAM. I use some applications (Parallels for Windows (1GB RAM), Firefox, mail, freemind, iTunes, Finder, Terminal and that's it), and I can observe that after some time memory is completely full and system's performance decreases.
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All the applications developed for use on Apple Machines are built to optimally use the memory available. But memory management for MacBook becomes critical when you open too many applications that are running simultaneously. This results in major memory overload.
Other 7 Tips to Reduce Memory Usage on Mac Manually. Using a Mac cleaning tool to free up memory on Mac is much easiesr and faster. And this way is highly recommended for time-saving clean up. However, if you want to free up memory without using third-party software, here are other 7 extra tips for you to do the job manually.
Once you experience your Mac slowing down, you should start analyzing the memory usage. If you don’t know how to check memory usage on Mac, the best application to start with is the Activity Monitor. You can easily find this application in the Utilities or you can simply type the name of the application in the Spotlight window.
Activity Monitor: Helpful Tool in Analyzing Memory Usage on Your Mac
Activity Monitor is a built-in application in MacOS which tells you everything that is running on your MacBook. It gives you a complete overview of your MacBook’s memory usage. Here you can find out what applications are currently running and how much memory is being utilized by each of the applications. It is an excellent tool in analyzing the memory usage as it gives you plenty of details on the resources being consumed by any application, including the memory being used, Number of threads utilized by each app, CPU usage, etc.
What's more, ths Activity Monitor shows how you can add different columns to check a particular resource being utilized by an application and play with the statistics to shut down what you don’t need and that eats too much of memory. To illustrate a few, let’s have a look at the memory page of Activity Monitor.
The memory page is very informative when you understand all that it is showing to you;
Memory Pressure: This graph gives you the usage of memory over a period of time. You can set the Update Frequency and set the intervals. The right-most bar is the current memory usage, going back in time as you move to the left of the graph. The color of the graph shows the usage level.
- Green – RAM Memory available.
- Yellow – RAM Memory still available, tasked by memory-management processes (like Compression)
- Red – RAM Memory completely used. This is the time where you should start shutting down some apps.
You can see the total installed RAM on your computer shown as,
Physical Memory: Total memory installed.
The part which you are really concerned about is the one marked as,
Memory Used: Total memory being used by the running apps and processes. Getting inside to have a deeper understanding of the memory distribution allows you to play with it and get the best performance.
- App Memory: Total memory used by all the apps/processes.
- Wired memory: As the name suggests, this memory is (virtually) hard-wired and you cannot make any changes to the processes using this memory. These are usually the primary processes of your Machine and they need the memory with the quickest access and cannot be swapped with the memory on disk.
- Compressed: The MacOS will compress a chunk of memory in the RAM to make more space for the utilization of other apps. You can see the column of compressed memory to see how much actual and compressed memory is used by each process or application.
Swap Used: The MacOS will utilize some space on the disk drive of your Mac. This is used to free up physical space on RAM for the applications requiring more intense use of memory.
Cached Files: The MacOS keeps the recently closed applications as cached files for quick loading once you restart the same application. However, this memory is available to be used by any new application if the same application is not started.
Running out of Space? Try The Quick Fix to Free Up Memory Space Here
When you are running out of space on your Mac and your memory pressure graph is constantly in the red. Your computer is slowing down and if you are thinking about how do I free up memory on my Mac, using a powerful Mac cleanup software is the quickest fix for you. Umate Mac Cleaner is beyond compare your first choice for Mac cleaning software you will find and let me tell you why.
Umate Mac Cleaner is an amazingly powerful tool to clean and offers a one-click solution for releasing more memory. No important files will be deleted through Umate Mac Cleaner so you don’t have to worry about accidentally harming your Mac. Its one of the main features - Clean Up Junk is designed to delete all the junk files which are slowing down the Mac system. You can use the Clean Up Junk feature to run a Quick Clean first.
Quick Clean will run an automatic scan to search, identify and delete the unnecessary files piled up on your system. Deleting those junk files have no effect on system performance, so you can safely remove them without consideration.
Once the Quick Clean has done its job and you still feel the need to make some more space available, the Clean Up Junk lets you run a Deep Clean on the Mac. Deep Clean shows you the files available on the system which can be deleted to make more space available on the Mac. It runs a scan and finds the items that can be deleted, and you can now choose which of these files you want to permanently remove from the system, then hit the big Clean button to remove them with single click.
Another very useful feature of Umate Mac Cleaner to lower memory usage on Mac is Manage Application & Extensions. Naturally, there are a few applications lying around over the chunks of your memory and these applications are not even being used. These unused applications and unnecessary extensions are hogging on the memory bytes which are needed for the new and more frequent applications. This feature of Umate Mac Cleaner is how to save memory on Mac by uninstalling the rarely used applications and their associated files. Along with the unused applications, it also targets the unnecessary extensions which are installed in your Mac. This feature will list down the applications with their usage statistics and you can choose which ones to remove to lower memory usage on your Mac.
Getting Umate Mac Cleaner for Mac memory management is unbelievably easy. All you need to do is get the app from iMyFone, install and launch the app and let it do the rest automatically. The app comes with a very intuitive user interface and is compatible with Macbook/iMac running MacOS 10.15-10.9.
Other 7 Tips to Reduce Memory Usage on Mac Manually
Using a Mac cleaning tool to free up memory on Mac is much easiesr and faster. And this way is highly recommended for time-saving clean up. However, if you want to free up memory without using third-party software, here are other 7 extra tips for you to do the job manually. Let’s check them out together!
1. Clean up the Desktop
No matter what computer you are using, you know that your desktop is filled with unnecessary and unused icons scattered all around the screen. Don’t worry; this is what we do on all our computers. But if you want to lower the memory usage on your Mac, you might want to steer away from cluttering your desktop. This might come as a surprise, but MacOS allows your desktop icons to be treated as priority applications and it keeps all the desktop icons in the active memory. This takes up space in your RAM which you definitely want to save.
2. Manage Memory Usage in Finder
The Finder application on Mac can sometimes take up a lot of memory of your system. You are thinking that Finder should not be taking up this much space, right. It is probably because the Finder application is set to show all files available on the system. Try changing the default display of Finder to not show All My Files. This will work wonders for you.
3. Force Quit Memory-eating Processes
In the Activity Monitor, you can see which applications are consuming most of the memory. These memory-hogging processes are slowing down your system. You can select to Force Quit these processes to save memory on your Mac.
4. Delete Browser Extensions
The add-ons and extensions on the internet browser are nice tools for quick access to features you need while surfing the internet. But more often than not, they are consuming more memory than they are being helpful. You can save a lot of memory on your Mac by deleting the unwanted browser extensions. Just launch the browser on your Mac, like Safari, Chrome and Firefox, and then go to Preferences to remove those unwanted extensions on the Extensions tab.
You can use Umate Mac Cleaner to remove the undesired extensions. Just launch the app and go to Manage Applications and Extensions and the memory management tool will list down all the extensions for you to choose and delete. You will be surprised at how many of these extensions are not even needed in your Mac.
5. Close Unwanted Finder Windows
Opening a number of Finder windows takes up a lot of memory, and it is incredible how much memory you can save by this little tip. You don’t need anything fancy for this. A keyboard shortcut is all you need; press Command + Option + W to close all the open windows on your Mac.
6. Disable Login Items
The items that are set to launch on every login are going to use a lot of memory space. Most of these login items are not essentially required for your day to day computing needs and you can easily get rid of them. Here are the simple steps to do that: Click the Apple icon > select System Preferences > Click Users & Groups > Select the login item you want to remove, then click the Remove.
Using Umate Mac Cleaner to Disable Startup Items is your one-click solution to fix this issue. Select the items you want to disable on your next login and you will start your Mac with a bunch of memory saved.
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7. Purge RAM in Terminal (for Advanced Users)
Open the terminal on your Mac and enter the command ‘sudo purge’. This feature requires admin rights so you would have to enter the password here then the system will clear the inactive memory. We strongly advise against using this method unless you know your way around your Machine.
If You Use Chrome Browser, Here's Bonus Tip to Lower Memory Usage
If you are using Google applications like Gmail, Google Drive, etc. This tip might be useful on how to lower memory usage on Mac. Google Chrome makes use of the system GPU for its processes to help load web pages super fast, however, this process takes a lot of memory on your system RAM. Fortunately, there is a way to control this. Use the Task Manager of Google Chrome to manage the memory available for use by Chrome, and you are good to go!
Anyway, You Should Keep Your Eye on Mac's Memory Usage
If your Mac is boosted up with 16 gigs of RAM memory, then you might have a lot of free space to use up for unnecessary applications. But with the basic 4 or 8GB RAM machine, you would require the monitoring more often. More applications running on the Mac means more memory usage. This makes it very important that you should keep a check on your applications. Learning to read and analyze the memory page of the Activity Monitor will be extremely useful in memory management for your Mac and keep your MacBook memory usage under check.
Conclusion
With these simple tips and tricks, you can bring your Mac back to its fast performance condition when the speed of your MacBook was unmatched to all the other computers. Using an application that can efficiently look after the system health will keep your Macbook hassle-free. Umate Mac Cleaner might just be the thing you were looking for, a application that comes with all-in-one package and all the features you need.
(Redirected from Mac OS memory management)
'About This Computer' Mac OS 9.1 window showing the memory consumption of each open application and the system software itself.
Free Up Memory Mac Os X
Historically, the classic Mac OS used a form of memory management that has fallen out of favor in modern systems. Criticism of this approach was one of the key areas addressed by the change to Mac OS X.
The original problem for the engineers of the Macintosh was how to make optimum use of the 128 KB of RAM with which the machine was equipped, on Motorola 68000-based computer hardware that did not support virtual memory.[1] Since at that time the machine could only run one application program at a time, and there was no fixedsecondary storage, the engineers implemented a simple scheme which worked well with those particular constraints. That design choice did not scale well with the development of the machine, creating various difficulties for both programmers and users.
Fragmentation[edit]
The primary concern of the original engineers appears to have been fragmentation - that is, the repeated allocation and deallocation of memory through pointers leading to many small isolated areas of memory which cannot be used because they are too small, even though the total free memory may be sufficient to satisfy a particular request for memory. To solve this, Apple engineers used the concept of a relocatable handle, a reference to memory which allowed the actual data referred to be moved without invalidating the handle. Apple's scheme was simple - a handle was simply a pointer into a (non relocatable) table of further pointers, which in turn pointed to the data.[2]If a memory request required compaction of memory, this was done and the table, called the master pointer block, was updated. The machine itself implemented two areas in memory available for this scheme - the system heap (used for the OS), and the application heap.[3]As long as only one application at a time was run, the system worked well. Since the entire application heap was dissolved when the application quit, fragmentation was minimized.
The memory management system had weaknesses; the system heap was not protected from errant applications, as would have been possible if the system architecture had supported memory protection, and this was frequently the cause of system problems and crashes.[4]In addition, the handle-based approach also opened up a source of programming errors, where pointers to data within such relocatable blocks could not be guaranteed to remain valid across calls that might cause memory to move. This was a real problem for almost every system API that existed. Because of the transparency of system-owned data structures at the time, the APIs could do little to solve this. Thus the onus was on the programmer not to create such pointers, or at least manage them very carefully by dereferencing all handles after every such API call. Since many programmers were not generally familiar with this approach, early Mac programs suffered frequently from faults arising from this.[5]
Palm OS and 16-bit Windows use a similar scheme for memory management, but the Palm and Windows versions make programmer error more difficult. For instance, in Mac OS, to convert a handle to a pointer, a program just de-references the handle directly, but if the handle is not locked, the pointer can become invalid quickly. Calls to lock and unlock handles are not balanced; ten calls to HLock are undone by a single call to HUnlock.[6] In Palm OS and Windows, handles are an opaque type and must be de-referenced with MemHandleLock on Palm OS or Global/LocalLock on Windows. When a Palm or Windows application is finished with a handle, it calls MemHandleUnlock or Global/LocalUnlock. Palm OS and Windows keep a lock count for blocks; after three calls to MemHandleLock, a block will only become unlocked after three calls to MemHandleUnlock.
Addressing the problem of nested locks and unlocks can be straightforward (although tedious) by employing various methods, but these intrude upon the readability of the associated code block and require awareness and discipline on the part of the coder.
Memory leaks and stale references[edit]
Awareness and discipline are also necessary to avoid memory 'leaks' (failure to deallocate within the scope of the allocation) and to avoid references to stale handles after release (which usually resulted in a hard crash—annoying on a single-tasking system, potentially disastrous if other programs are running).
Switcher[edit]
The situation worsened with the advent of Switcher, which was a way for a Mac with 512KB or more of memory to run multiple applications at once.[7] This was a necessary step forward for users, who found the one-app-at-a-time approach very limiting. Because Apple was now committed to its memory management model, as well as compatibility with existing applications, it was forced to adopt a scheme where each application was allocated its own heap from the available RAM.[8]The amount of actual RAM allocated to each heap was set by a value coded into the metadata of each application, set by the programmer. Sometimes this value wasn't enough for particular kinds of work, so the value setting had to be exposed to the user to allow them to tweak the heap size to suit their own requirements. While popular among 'power users', this exposure of a technical implementation detail was against the grain of the Mac user philosophy. Apart from exposing users to esoteric technicalities, it was inefficient, since an application would be made to grab all of its allotted RAM, even if it left most of it subsequently unused. Another application might be memory starved, but would be unable to utilize the free memory 'owned' by another application.[3]
While an application could not beneficially utilize a sister application's heap, it could certainly destroy it, typically by inadvertently writing to a nonsense address. An application accidentally treating a fragment of text or image, or an unassigned location as a pointer could easily overwrite the code or data of other applications or even the OS, leaving 'lurkers' even after the program was exited. Such problems could be extremely difficult to analyze and correct.
Switcher evolved into MultiFinder in System 4.2, which became the Process Manager in System 7, and by then the scheme was long entrenched. Apple made some attempts to work around the obvious limitations – temporary memory was one, where an application could 'borrow' free RAM that lay outside of its heap for short periods, but this was unpopular with programmers so it largely failed to solve the problems. Apple's System 7 Tune-up addon added a 'minimum' memory size and a 'preferred' size—if the preferred amount of memory was not available, the program could launch in the minimum space, possibly with reduced functionality. This was incorporated into the standard OS starting with System 7.1, but still didn't address the root problem.[9]
Virtual memory schemes, which made more memory available by paging unused portions of memory to disk, were made available by third-party utilities like Connectix Virtual, and then by Apple in System 7. This increased Macintosh memory capacity at a performance cost, but did not add protected memory or prevent the memory manager's heap compaction that would invalidate some pointers.
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32-bit clean[edit]
Originally the Macintosh had 128 kB of RAM, with a limit of 512 kB. This was increased to 4 MB upon the introduction of the Macintosh Plus. These Macintosh computers used the 68000 CPU, a 32-bit processor, but only had 24 physical address lines. The 24 lines allowed the processor to address up to 16 MB of memory (224 bytes), which was seen as a sufficient amount at the time. The RAM limit in the Macintosh design was 4 MB of RAM and 4 MB of ROM, because of the structure of the memory map.[10] This was fixed by changing the memory map with the Macintosh II and the Macintosh Portable, allowing up to 8 MB of RAM.
Because memory was a scarce resource, the authors of the Mac OS decided to take advantage of the unused byte in each address. The original Memory Manager (up until the advent of System 7) placed flags in the high 8 bits of each 32-bit pointer and handle. Each address contained flags such as 'locked', 'purgeable', or 'resource', which were stored in the master pointer table. When used as an actual address, these flags were masked off and ignored by the CPU.[4]
While a good use of very limited RAM space, this design caused problems when Apple introduced the Macintosh II, which used the 32-bit Motorola 68020 CPU. The 68020 had 32 physical address lines which could address up to 4 GB (232 bytes) of memory. The flags that the Memory Manager stored in the high byte of each pointer and handle were significant now, and could lead to addressing errors.
In theory, the architects of the Macintosh system software were free to change the 'flags in the high byte' scheme to avoid this problem, and they did. For example, on the Macintosh IIci and later machines, HLock() and other APIs was rewritten to implement handle locking in a way other than flagging the high bits of handles. But, many Macintosh application programmers and a great deal of the Macintosh system software code itself accessed the flags directly rather than using the APIs, such as HLock(), which had been provided to manipulate them. By doing this they rendered their applications incompatible with true 32-bit addressing, and this became known as not being '32-bit clean'.
In order to stop continual system crashes caused by this issue, System 6 and earlier running on a 68020 or a 68030 would force the machine into 24-bit mode, and would only recognize and address the first 8 megabytes of RAM, an obvious flaw in machines whose hardware was wired to accept up to 128 MB RAM – and whose product literature advertised this capability. With System 7, the Mac system software was finally made 32-bit clean, but there were still the problem of dirty ROMs. The problem was that the decision to use 24-bit or 32-bit addressing has to be made very early in the boot process, when the ROM routines initialized the Memory Manager to set up a basic Mac environment where NuBus ROMs and disk drivers are loaded and executed. Older ROMs did not have any 32-bit Memory Manager support and so was not possible to boot into 32-bit mode. Surprisingly, the first solution to this flaw was published by software utility company Connectix, whose 1991 product MODE32 reinitialized the Memory Manager and repeated early parts of the Mac boot process, allowing the system to boot into 32-bit mode and enabling the use of all the RAM in the machine. Apple licensed the software from Connectix later in 1991 and distributed it for free. The Macintosh IIci and later Motorola based Macintosh computers had 32-bit clean ROMs.
It was quite a while before applications were updated to remove all 24-bit dependencies, and System 7 provided a way to switch back to 24-bit mode if application incompatibilities were found.[3] By the time of migration to the PowerPC and System 7.1.2, 32-bit cleanliness was mandatory for creating native applications and even later Motorola 68040 based Macs could not support 24-bit mode.[6][11]
Object orientation[edit]
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The rise of object-oriented languages for programming the Mac – first Object Pascal, then later C++ – also caused problems for the memory model adopted. At first, it would seem natural that objects would be implemented via handles, to gain the advantage of being relocatable. These languages, as they were originally designed, used pointers for objects, which would lead to fragmentation issues. A solution, implemented by the THINK (later Symantec) compilers, was to use Handles internally for objects, but use a pointer syntax to access them. This seemed a good idea at first, but soon deep problems emerged, since programmers could not tell whether they were dealing with a relocatable or fixed block, and so had no way to know whether to take on the task of locking objects or not. Needless to say this led to huge numbers of bugs and problems with these early object implementations. Later compilers did not attempt to do this, but used real pointers, often implementing their own memory allocation schemes to work around the Mac OS memory model.
While the Mac OS memory model, with all its inherent problems, remained this way right through to Mac OS 9, due to severe application compatibility constraints, the increasing availability of cheap RAM meant that by and large most users could upgrade their way out of a corner. The memory wasn't used efficiently, but it was abundant enough that the issue never became critical. This is ironic given that the purpose of the original design was to maximise the use of very limited amounts of memory. Mac OS X finally did away with the whole scheme, implementing a modern sparse virtual memory scheme. A subset of the older memory model APIs still exist for compatibility as part of Carbon, but map to the modern memory manager (a threadsafe malloc implementation) underneath.[6]Apple recommends that Mac OS X code use malloc and free 'almost exclusively'.[12]
References[edit]
- ^Hertzfeld, Andy (September 1983), The Original Macintosh: We're Not Hackers!, retrieved 2010-05-10
- ^Hertzfeld, Andy (January 1982), The Original Macintosh: Hungarian, archived from the original on 2010-06-19, retrieved 2010-05-10
- ^ abcmemorymanagement.org (2000-12-15), Memory management in Mac OS, archived from the original on 2010-05-16, retrieved 2010-05-10
- ^ abHertzfeld, Andy, The Original Macintosh: Mea Culpa, retrieved 2010-05-10
- ^Apple Computer (1985-10-01), Technical Note OV09: Debugging With PurgeMem and CompactMem, retrieved 2010-05-10
- ^ abcLegacy Memory Manager Reference, Apple Inc, 2007-06-27, retrieved 2010-05-10
- ^Hertzfeld, Andy (October 1984), The Original Macintosh: Switcher, retrieved 2010-05-10
- ^Mindfire Solutions (2002-03-06), Memory Management in Mac OS(PDF), p. 2, retrieved 2010-05-10
- ^'System 7.1 upgrade guide'(PDF). Archived from the original(PDF) on 2016-03-04. Retrieved 2015-05-26.
- ^'memory maps'. Osdata.com. 2001-03-28. Retrieved 2010-05-11.
- ^Apple Computer (1991-01-01), Technical Note ME13: Memory Manager Compatibility, retrieved 2010-05-10
- ^Memory Allocation Recommendations on OS X, Apple Inc, 2005-07-12, retrieved 2009-09-22
External links[edit]
- Macintosh: ROM Size for Various Models, Apple Inc, 2000-08-23, retrieved 2009-09-22
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