How Virtual Memory Saves The Day

Contributed by Jennifer Goldman

Virtual memory, what’s that? You may not know what virtual memory is, but you can bet that if you’re a computer user, it makes your life a heck of a lot easier. The average computer today has about 32 to 64 megabytes of memory. That’s not very much considering all the complex programs we usually have running at any given time. Virtual memory frees up the data storage space you need to keep multiple programs running simultaneously. Instead of you having to manually juggle data around to make space, your operating system does it for you, by falling back on a very useful mechanism or operating system called virtual memory. Otherwise your programs would crash when you filled up RAM (random access memory) space and you’d only be able to use one or two at a time. Imagine how inconvenient that would be!

When the physical memory of a computer is exceeded due to multiple programs running simultaneously, your computer needs to store some of the data on disk, transferring it back and forth to your physical memory as space opens up. This poses a few problems. For one, disks are very slow. Secondly a programmer would need to implement a separate software program to determine and direct what bits of data would need to go where; some data is not compatible, while other pieces of data depend on each other in terms of interlaced programming code.

Fortunately, virtual memory permits software to use more of the main memory that the computer’s central processing unit needs to read software and to record and implement functions performed within that program. When the computer’s physical memory spills over with data, virtual memory serves to move and exchange temporary data from the computer’s physical memory to a newly created hard disk.

Virtual memory is able to create more memory than your computer actually has by fragmenting programs into small pieces. Virtual memory takes these pieces, known as pages, and transfers the maximum number it can to the computers physical memory. If the programs you’re using need more pages to run properly, virtual memory transfers them to a new temporary drive. So, essentially, virtual memory switches bits of information from the physical memory to the disk, with the part of the disk retaining info that is not on the physical drive (called the swap file). It does you the favor of tracking what program is hogging up what portions of the computer’s memory space and assigns each program the amount of memory required, taking it where it can get it.

In other words, virtual memory lets software perform its functions in a memory address space that doesn’t have to be attached to the physical memory of your computer. When virtual memory is activated, your computer’s hardware coverts the memory location address created by your software into either a true memory location in the computer’s physical memory or it makes a virtual memory exception where bits of information are traded among the physical memory and the disk. So, both hardware and software are involved in the virtual memory process. Virtual memory uses disk space as though it were actually part of the physical memory of your computer’s central processing unit.

You can even adjust your computer’s virtual memory in order to make your computer run faster. Here’s how to assign more hard disk space to virtual memory so when your random access memory is packed full you’ll have more temporary space. As an added benefit, you’ll increase the efficiency of your computer when it runs programs.

You can alter your virtual memory settings by first, clicking on My Computer and choosing Properties on the menu. Next click on the performance tab and then choose Virtual Memory. Select the feature that allows you to specify your own virtual memory setting. Choose your fastest hard drive from the hard disk drop-down list. Last but not least, ensure that the maximum and minimum numbers of random access memory match. If you want to achieve the most possible memory, multiply the random access memory of your system by 2.5 and enter that figure in the maximum and minimum random access memory fields. Doing so will enable you to increase your random access memory by 2 ½ times!

About the Author:
Jennifer Goldman is a freelance writer, editor, and proofreader living in Denver, Colorado.

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