Buy the ARP T-Shirt! BIOS Optimization Guide Money Savers!
 
 01 December 2004
 N/A
  N/A
 Tweaks
 Dr. Adrian Wong
 4.1
 Discuss here !
 514067
 
   
Hands On With The AMD Radeon R9 Fury X, R9 Fury X2 & R9 Nano
AMD not only set up a wide range of sample systems to demonstrate the performance of ... Read here
Desktop Graphics Card Comparison Guide Rev. 31.6
Covering 628 desktop graphics cards, this comprehensive comparison allows you ... Read here
   
Buy The BOG Book Subscribe To The BOG! Latest Money Savers!
Virtual Memory Optimization Guide Rev. 4.1
Digg! Reddit!Add to Reddit | Bookmark this article:

Virtual Memory

Back in the 'good old days' of command prompts and 1.2MB floppy disks, programs needed very little RAM to run because the main (and almost universal) operating system was Microsoft DOS and its memory footprint was small. That was truly fortunate because RAM at that time was horrendously expensive. Although it may seem ludicrous, 4MB of RAM was considered then to be an incredible amount of memory.

However when Windows became more and more popular, 4MB was just not enough. Due to its GUI (Graphical User Interface), it had a larger memory footprint than DOS. Thus, more RAM was needed.

Unfortunately, RAM prices did not decrease as fast as RAM requirement had increased. This meant that Windows users had to either fork out a fortune for more RAM or run only simple programs. Neither were attractive options. An alternative method was needed to alleviate this problem.

The solution they came up with was to use some space on the hard disk as extra RAM. Although the hard disk is much slower than RAM, it is also much cheaper and users always have a lot more hard disk space than RAM. So, Windows was designed to create this pseudo-RAM or in Microsoft's terms - Virtual Memory, to make up for the shortfall in RAM when running memory-intensive programs.

 

How Does It Work?

Virtual memory is created using a special file called a swapfile or paging file.

Whenever the operating system has enough memory, it doesn't usually use virtual memory. But if it runs out of memory, the operating system will page out the least recently used data in the memory to the swapfile in the hard disk. This frees up some memory for your applications. The operating system will continuously do this as more and more data is loaded into the RAM.

However, when any data stored in the swapfile is needed, it is swapped with the least recently used data in the memory. This allows the swapfile to behave like RAM although programs cannot run directly off it. You will also note that because the operating system cannot directly run programs off the swapfile, some programs may not run even with a large swapfile if you have too little RAM.

 



 
   
Kingston DataTraveler Elite 3.0 USB 3.0 Flash Drive Review Rev. 2.0
Intel Core 2 Processor Performance Comparison Guide Rev. 2.7
ASUS ENGTX280 TOP GeForce GTX 280 Graphics Card Review
NVIDIA GeForce 8800 GT Technology Report
Seagate 750GB Pushbutton Backup Review
NVIDIA GeForce 7900 GTX & 7900 GT Tech Report
NVIDIA GeForce 7800 GT Review
Fantasy Mini Mouse Review
512MB Mushkin PC4000 Dual Pack Review
Cooler Master HAC-V81 @ X-Dream Review

 


Copyright © Tech ARP.com. All rights reserved.