What a page file is and why you might need to increase it

Your page file is a section of your hard drive that Windows uses as overflow memory. When your computer runs out of RAM — the fast memory that programs use while they're running — Windows moves data to the page file instead of stopping the program. This keeps things running, but slower, because a hard drive is much slower than RAM.

You might notice your computer slowing down when you have many programs open at once, or when a single program uses a lot of memory. Increasing your page file size gives Windows more space to store that overflow data. This won't make your computer as fast as having more actual RAM, but it can prevent crashes when you run out of memory entirely.

The default page file size is usually 1.5 times your total RAM. If you have 8 GB of RAM, Windows sets the page file to about 12 GB by default. You can increase this manually if you find your computer frequently runs out of memory.

Key Takeaways

  • The page file is hard drive space Windows uses when RAM fills up, and increasing it prevents crashes but not slowness.
  • You change page file size in Virtual Memory settings, which you reach through System Properties in Windows.
  • Set a custom size with an initial size and maximum size, both measured in megabytes, rather than letting Windows manage it automatically.
  • You need to restart your computer for page file changes to take effect.
  • Increasing the page file only helps if you have free hard drive space available.

How to access Virtual Memory settings on Windows

Open the Start menu and type "sysdm.cpl" into the search box, then press Enter. This opens System Properties directly. You can also right-click "This PC" or "My Computer" on your desktop, select Properties, then click "Advanced system settings" on the left side.

Once System Properties is open, click the "Advanced" tab at the top. Under "Performance," click the "Settings" button. A new window opens — click the "Advanced" tab again. At the bottom, you'll see "Virtual Memory" with a "Change" button. Click it.

Setting a custom page file size

The Virtual Memory window shows your current page file settings. At the top, uncheck the box that says "Automatically manage paging file size for all drives." This lets you set your own numbers instead of letting Windows decide.

Select the drive where you want the page file (usually your C: drive, where Windows is installed). Below that, you'll see two fields: "Initial size" and "Maximum size," both in megabytes. The initial size is what Windows uses most of the time; the maximum size is the limit if it needs more.

A common starting point is to set both to 1.5 times your RAM in megabytes. If you have 8 GB of RAM, that's 8,192 MB, so you'd set both fields to around 12,288 MB. You can set them to the same number, or set the initial size lower and the maximum higher — for example, 8,192 and 16,384 — to let Windows use more space only when needed.

Click "Set," then "OK" to save your changes. Windows will ask you to restart your computer. Restart now so the new page file size takes effect.

Checking available hard drive space before you increase the page file

Before you increase the page file, make sure you have enough free space on your hard drive. Open File Explorer, right-click your C: drive, and select Properties. The pie chart shows how much space is used and how much is free. You need at least as much free space as the maximum page file size you're planning to set.

If your hard drive is nearly full, increasing the page file won't help much — you'll run into storage limits instead. In that case, consider deleting old files, uninstalling programs you don't use, or moving large files to an external drive before you increase the page file.

When a larger page file won't solve the problem

Increasing the page file helps when you're running out of RAM, but it doesn't fix every slowness problem. If your computer is slow even when you're not running many programs, the issue is probably something else — a full hard drive, a failing drive, malware, or outdated drivers.

You can check how much RAM you're actually using. Open Task Manager by pressing Ctrl+Shift+Esc. Click the "Performance" tab, then "Memory" on the left. The graph shows your current RAM use. If it's consistently above 90%, increasing the page file will help. If it's below 70% most of the time, your slowness is coming from somewhere else.

Similarly, if you're running out of hard drive space (less than 10% free), increasing the page file will make things worse by taking up more of that space. In that situation, free up space first.

Changing the page file back to automatic management

If you set a custom page file size and later want Windows to manage it automatically again, return to Virtual Memory settings the same way: System Properties > Advanced tab > Performance Settings > Advanced tab > Virtual Memory Change button.

Check the box that says "Automatically manage paging file size for all drives." Click "Set," then "OK," and restart your computer. Windows will go back to its default calculation based on your RAM.

Page file size on different hard drive types

If you have an SSD (solid-state drive), you can still increase the page file, but be aware that SSDs have a limited number of write cycles. Putting a large page file on an SSD means more data being written to it over time. Many people put the page file on a traditional hard drive instead if they have one, to preserve the SSD's lifespan.

To do this, uncheck "Automatically manage paging file size for all drives," set the page file to 0 on your SSD, then set a custom size on your traditional hard drive. This requires you to have both types of drives in your computer.

Frequently Asked Questions

How much should I increase my page file?

Start with 1.5 times your total RAM. If you have 16 GB of RAM, try 24,576 MB. You can increase it further if you still run out of memory, but there's no benefit to setting it much larger than your RAM — at that point, adding actual RAM is more cost-effective.

Will a bigger page file make my computer faster?

No. A page file is slower than RAM because hard drives are slower than memory chips. A larger page file prevents crashes when you run out of RAM, but it won't make your computer faster. If you want speed, adding more RAM is the real solution.

Can I set the page file on an external drive?

No. Windows only allows the page file on internal drives. If you only have one internal drive and it's nearly full, you'll need to free up space on it or add another internal drive before you can increase the page file.

What happens if I set the page file too high?

If you set it higher than your available hard drive space, Windows will reduce it automatically or show an error. There's no harm in setting it high — it just wastes hard drive space if you don't actually need it. You can always lower it later.

Do I need to restart after changing the page file?

Yes. Windows requires a restart for page file changes to take effect. You'll see a prompt asking to restart when you click OK in Virtual Memory settings.