When dealing with a slow computer you often come across the terms virtual memory and the page file. Many myths circulate around them about a miraculous speedup. Let us explain what it really is and whether it pays to interfere with it.

What virtual memory is

Operating memory (RAM) is fast memory where the computer stores what it is currently working with. When RAM fills up, Windows helps itself by temporarily setting part of the data aside on the disk. This place on the disk is called the page file, and the whole mechanism is virtual memory.

Put differently, virtual memory is an emergency extension of operating memory using the disk. Thanks to it the computer does not crash even when RAM fills up.

Swap, page file, paging file: different names for the same thing

The same thing is called differently in different systems, which often confuses people:

  • Windows: page file or paging file, physically the file pagefile.sys.
  • Linux and macOS: swap (swap space), either a separate partition (swap partition) or a swap file.

The process of moving parts of memory (pages) between RAM and the disk is technically called paging, and moving whole processes swapping. The principle is always the same: when RAM is not enough, part of the data is temporarily set aside on the disk.

How it relates to RAM

It is important to understand the difference:

  • RAM is fast. What you are currently using runs there.
  • The page file on the disk is much slower. It serves as a rescue reserve when RAM is not enough.

When the computer often reaches for the page file, it is a sign that you have little RAM. Then the system slows down, because instead of fast memory it has to wait for the slower disk. There is an article on choosing memory, how to choose RAM.

Do you need to change the size manually?

In the vast majority of cases no. Windows manages the size of the page file automatically and does it well. We recommend manual intervention only for advanced users with a specific reason. For an ordinary user the rule is: leave it to the system.

Speedup myths

  • Myth: enlarging the page file speeds up the computer. It does not. The page file is on the disk, which is slower than RAM. A real speedup comes from more RAM, not a bigger file on the disk.
  • Myth: disabling the page file helps. It rather harms. Some programs need it and may crash after it is disabled.
  • Truth: a fast disk helps virtual memory too. On an SSD, paging is faster than on an old platter disk, more in the article is it worth switching to an SSD.

What really helps with a memory shortage

  • Add RAM. The most effective solution, if the computer allows it.
  • Close unnecessary programs and browser tabs that eat memory.
  • Have the system on an SSD, so that paging is brisk too.

There are more tips in the article how to speed up a slow computer.

Conclusion

Virtual memory and the page file are an emergency reserve that helps when operating memory fills up. But it is a slower aid on the disk, not a replacement for RAM. You do not need to change the size manually, Windows handles it itself, and enlarging the file will not speed up the computer. If the system often slows down, the real solution is more RAM and the system on an SSD.

Is your computer slowing down and are you considering a memory upgrade? Get in touch, we will advise and upgrade it.

This article is part of our Software and system overview.