How to Fix Game Lag and RAM Stutter When Games Are Not Using All Your RAM

So you just upgraded to 16GB or 32GB of RAM, you fire up your favorite game, open Task Manager, and notice the game is only using 4 to 6GB while you are still getting stutters. That is really frustrating, and I know because I have been in the exact same position.

The good news is that in most cases, this is not a hardware problem. It is Windows getting in the way. There are background services, memory settings, and a few registry tweaks that are quietly eating into your available RAM and preventing games from using what they need.

In this guide, I will show you exactly what to do, step by step. By the time you are done, your system will be giving your games the memory they deserve.

Step 1: Check If Your RAM Is Actually Running at Full Speed

Before touching any settings, you need to verify that your RAM is running correctly. A lot of people have RAM installed that runs slower than it should, and that alone causes stutter and poor gaming performance.

Download CPU-Z for free, open it, and click the Memory tab. Here is what you are looking for:

• DRAM Frequency – If you have DDR4-3200 RAM, this should show around 1600 MHz. If it shows 1066 or 1333 MHz, your RAM is stuck in a slow fallback mode. You need to go into your BIOS and enable XMP or EXPO.
• Channel – This must say Dual. If it says Single, you are missing out on 30 to 40 percent of your RAM bandwidth. This is a huge cause of gaming stutter. Check your motherboard manual and reinstall your sticks in the correct slots.

Fixing the RAM speed and channel configuration alone can make a bigger difference than any software tweak. Do this first.

Step 2: Disable SysMain (Superfetch) to Free Up RAM for Games

SysMain, which used to be called Superfetch, is a Windows service that tries to predict which apps you will use next and preloads them into RAM. The idea is fine, but in practice, it competes with your games for memory and can cause stutters, especially when a game is trying to load a new area or asset.

Here is how to turn it off:

1. Press Win + R, type services.msc, and press Enter
2. Scroll down the list and find SysMain
3. Double-click it, change the Startup type to Disabled, then click Stop and then OK

Once you disable SysMain, Windows stops filling your RAM with preloaded apps. Your games get access to clean, free memory whenever they need it instead of fighting for it.

Step 3: Disable Windows Search to Reduce Background RAM Usage

Windows Search runs a constant background indexing process that scans your files so search results are fast. That background scanning uses both RAM and CPU. During gaming sessions, this can cause micro-stutters at the worst moments.

To disable it:

1. Open services.msc again (Win + R, then services.msc)
2. Find Windows Search in the list
3. Double-click it, set Startup type to Disabled, click Stop, then click OK

Your file search will still work, it just will not have pre-indexed results so it takes a second longer. For gaming that is a perfectly fine trade. You can always re-enable it if you need it back.

Step 4: Fix Your Virtual Memory (Pagefile) Settings

Virtual memory is space on your drive that Windows uses as extra RAM when your physical RAM fills up. Some guides tell you to set this to a custom value or disable it entirely if you have a lot of RAM. I do not recommend that. Having no pagefile or one that is too small can cause crashes and instability.

What you want is to let Windows manage it automatically:

1. Press Win + S and search for Adjust the appearance and performance of Windows
2. Click the Advanced tab at the top
3. Under Virtual memory, click Change
4. Make sure Automatically manage paging file size for all drives is checked at the top
5. If it is already checked, you are good. If someone changed it to a custom size or disabled it, set it back to automatic and click OK

Letting Windows manage the pagefile automatically means it adjusts based on what your system actually needs. You avoid the crashes that come from setting it too low or zero.

Step 5: Registry Tweak to Prioritize Application Memory

Deep inside the Windows Registry there is a value called LargeSystemCache. By default on desktop systems it is set to 0, which tells Windows to keep more memory reserved for system caches. Changing it to 1 shifts the priority toward applications, meaning your games get more of that RAM.

Here is how to change it:

1. Press Win + R, type regedit, and press Enter
2. Navigate to this path: HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management
3. On the right side, find LargeSystemCache
4. Double-click it and change the value from 0 to 1
5. Click OK, then restart your PC for the change to take effect

Important note: This tweak works best on systems with 16GB of RAM or more. If you have 8GB or less, do not change this value because it can actually hurt performance on memory-limited systems.

Step 6: Disable Memory Compression in PowerShell

Windows 10 and 11 both use a feature called Memory Compression, which compresses the data stored in RAM so more can fit. When RAM fills up, this helps. But the compression and decompression work falls on your CPU, and during gaming that extra CPU load can cause stutter.

You can disable it with one PowerShell command:

1. Right-click the Start button and select Windows PowerShell (Admin) or Terminal (Admin)
2. Type the following command and press Enter:

Disable-MMAgent -mc

3. Restart your PC

If you ever want memory compression back, just open Admin PowerShell again and run Enable-MMAgent -mc. It is fully reversible.

Quick Reference: All Fixes in One Table

Frequently Asked Questions