What Is the Virtual Memory Swap File?

RAM is part of the computer's virtual memory.

Random access memory or RAM is a computer's physical system memory. The physical memory is used to run applications. When this memory is overtaxed, the computer relies on virtual memory to help run programs.

Virtual Memory

When system memory runs low, Windows uses space allocated from the hard disk drive to act as RAM. This is the "virtual memory." The maximum amount of allocated space is usually equal to half the amount of RAM installed. This gives the computer 50 percent more memory to run applications

Swap Files

Swap files, also known as page files, are the temporary storage areas used in the virtual memory.

Swapping

When RAM space becomes available, the memory management unit (MMU) swaps the temporary files back into physical memory files. The act of moving the files is known as "swapping" or "paging."

File Address Mapping

Part of the MMU memory stores the Translation Look-aside Buffer (TLB). This is a table that helps map virtual file addresses to the physical files replacing them.

References

• Windows Support Center: Virtual Memory in Windows XP
• Microsoft Support: RAM, Virtual Memory, Pagefile and all that stuff
• Microsoft Support: How to configure paging files for optimization and recovery in Windows XP
• Javvin: MMU: Memory Management Unit

Resources

• Windows: What is virtual memory?