FPS Drop and Stutter Cause Checker

Is your PC game dropping frames or stuttering? Pick your symptoms to see the likely causes, how to check them and how to fix them.

What kind of lag is it?
How does the frame rate drop?
Does it get worse when... Pick all that apply
More detail (optional)
GPU usage in Task Manager while playing

Open Task Manager with Ctrl+Shift+Esc and watch GPU on the Performance tab while playing. The value shows the busiest GPU engine.

PC type

Causes that match your symptoms

Second monitor

Many people report game stutter when mixing monitors with different refresh rates or playing video on a second monitor. It isn't a confirmed cause, so compare it yourself.

Possible

How to check

  1. Stop the video on the second monitor, or unplug it for a moment, and compare the same scene.

How to fix

  1. Check both monitors' refresh rates in Settings > System > Display > Advanced display.
  2. Enable G-SYNC only on the one monitor you game on.

Also worth checking

Hardware-accelerated GPU scheduling Possible

A Windows setting that lets the graphics card handle GPU scheduling. Some report stutter after switching it, but that isn't a confirmed cause, and DLSS Frame Generation on RTX 40 and 50 series needs it on.

How to check

  1. Check whether it is on in Settings > System > Display > Graphics > default graphics settings.

How to fix

  1. If stutter started after you changed it, switch it back, restart and compare.
  2. Keep it on if you use DLSS Frame Generation.

Settings Lutimize can changeTurn off hardware-accelerated GPU scheduling

Common causes of FPS drops and stutter

Pick your symptoms above and the checker narrows these down and shows how to check and fix each one.

Hardware limits

  • Graphics card limit

    The graphics card is working flat out and still cannot deliver more frames. Above 96% GPU utilization, the graphics card sets your frame rate.

  • CPU limit

    The graphics card sits idle while it waits for the CPU to prepare the next frame.

  • Not enough video memory (VRAM)

    Texture quality uses a lot of video memory. When it runs short you can get periodic stutter or late-loading textures, and lowering texture quality smooths things out.

  • Low RAM or single channelPossible

    When a game needs more memory than you have, Windows moves some of it to disk, which is slower than RAM and can cause stutter. With only one memory stick installed, bandwidth is lower than in dual channel.

  • Game installed on a hard drive (HDD)

    Games keep reading data from disk while you play. Hard drives are slow and can hitch when you enter new areas, and an SSD can reduce stutter.

Settings and drivers

  • Frame rate cap or V-Sync

    A frame rate cap or V-Sync stops FPS at a set number. V-Sync causes stutter and input lag whenever the frame rate falls below the refresh rate.

  • Monitor set to 60Hz

    Even a high refresh rate monitor such as 144Hz only updates 60 times a second if Windows is set to 60Hz.

    Monitor Refresh Rate Test
  • Game running on integrated graphics

    Laptops default to integrated graphics to save battery, and a game left there runs far slower. On desktops, a monitor cable in the motherboard port can do the same.

  • Heat throttling

    CPUs and graphics cards lower their own clocks and power as they approach their temperature limit. If performance is fine at first and drops over time, this is the first thing to suspect.

  • Shader compilation

    A common cause of stutter: the game pauses briefly while compiling shaders during play. Compiled shaders are cached so it eases next time, and a new driver clears that cache.

  • Second monitorPossible

    Many people report game stutter when mixing monitors with different refresh rates or playing video on a second monitor. It isn't a confirmed cause, so compare it yourself.

  • Graphics driver

    Problems that start after a Windows Update are often fixed by going back to the previous driver. Lower performance in some games after the October 2025 Windows 11 update was also fixed with an NVIDIA driver.

  • High mouse polling ratePossible

    A mouse with a very high polling rate makes the CPU process that many more inputs, which can cause stutter when the CPU is busy.

    Mouse Polling Rate Test

Windows and background apps

  • Power mode or laptop battery

    If the Windows power mode leans toward efficiency, it saves battery rather than maximizing performance. Laptops keep separate values for plugged in and on battery.

  • Discord overlay and Clips

    Discord's game overlay can be behind lag or crashes in a game, and on lower-end PCs Clips can affect game performance too.

  • Background recording

    Xbox Game Bar background recording keeps using PC resources and can affect game performance. Higher recording quality and frame rate add to the load.

  • Background programs

    Programs, browser tabs and updates running alongside the game share the CPU, memory and disk. The more you keep open, the more performance can drop.

  • Fullscreen optimizations and windowed modePossible

    Windows runs fullscreen games like an optimized window, and handles windowed games with 'Optimizations for windowed games'. Many people link these to stutter after alt-tabbing, but that isn't a confirmed cause.

  • Memory integrity (core isolation)Possible

    A security feature that protects the Windows kernel from malware; it costs more performance on CPUs older than Intel 7th gen or AMD Zen 2. From October 2026, Windows updates start turning it on for eligible PCs, so a drop after an update may come from this.

  • Hardware-accelerated GPU schedulingPossible

    A Windows setting that lets the graphics card handle GPU scheduling. Some report stutter after switching it, but that isn't a confirmed cause, and DLSS Frame Generation on RTX 40 and 50 series needs it on.

How this checker works

Causes that match your symptoms directly come first; ones that can appear alongside them come after.

Causes that many users report but that aren't confirmed are marked 'Possible'.

We don't show scores or numbers like 'X% more FPS'. There are no reliable figures behind them.

Frequently asked questions

My frame rate drops when Discord is open

Turn off Discord's game overlay for the game that lags or crashes, and on lower-end PCs try turning off Clips too. If screen sharing stutters, turn off hardware acceleration.

It stutters after I alt-tab

It may be related to Windows fullscreen optimizations or windowed game settings, but that isn't certain. Compare the in-game fullscreen and borderless window modes.

It runs fine, then drops after a few minutes

If it drops over time, suspect heat first. Clean the dust from vents and fans, and keep laptops on a hard, flat surface.

GPU usage is low but the frame rate is low too

Usually the graphics card is idle while it waits for the CPU (a CPU limit), and a frame cap or V-Sync also makes usage look low. On a laptop, also check whether the game runs on integrated graphics.

The game stutters when video plays on my second monitor

Many people report it, but it isn't a confirmed cause. Compare with the video stopped or the second monitor unplugged, and enable G-SYNC only on the monitor you game on.

Is my game lag caused by my PC or my internet?

If the picture hitches and the FPS counter drops with it, it is a PC performance (frame) problem. If FPS holds but characters teleport or hits land late, it is a connection problem (ping or packet loss).

My FPS is high but the game still stutters

Even with a high average FPS, a few late frames make the picture hitch. If it only stutters in new areas, suspect shader compilation; if it stutters at regular intervals, check background recording, apps running alongside the game and graphics memory.

What this tool does not do

  • It doesn't measure your PC. It only narrows down likely causes from the symptoms you pick.
  • It doesn't tell you to edit the registry by hand.
  • To see whether your graphics card or CPU is enough for a game, use PC Bottleneck Check.

Last reviewed 2026-11-07