What is "Full Screen Optimization" mode in games and why does it break some titles?

If you play on PC, you've probably heard of the mysterious Windows setting called mode “Full Screen Optimizations” in gamesIn other words, fullscreen optimizations. It's mentioned in almost every "boost your FPS" video on YouTube, in Steam forums, and in technical discussions, but it's rarely explained properly what it actually does, when it's advisable to disable it, and why it makes a huge difference for some players... while for others it doesn't budge a single frame.

In recent years many users have noticed that, in certain games, when disable full-screen optimizations and/or overlays such as the one for SteamThe GPU goes from 60-70% usage to constantly hovering around 99% load, while the CPU gets a bit more breathing room. Others, however, have found that it doesn't affect them at all, especially in modern titles with APIs like DirectX 12Let's break down what's happening, how this mode affects your performance, what role overlays (Steam, GeForce Experience, Discord, etc.) play, and how to check on your own computer if it's affecting your FPS.

What is “Full Screen Optimizations” mode in Windows?

The mode of “Fullscreen optimizations” is a feature introduced by Microsoft in Windows 10 with the goal of improving the full-screen gaming and video experience. On paper, its function is to combine the best of the exclusive full-screen mode and the borderless window, to offer lower latency, better overlay compatibility, and smoother window switching.

Traditionally, a game could work in Exclusive full-screen modewhere the application takes full control of the screen and the presentation buffer, or in windowed mode/borderless windowwhere the image passes through the desktop compositor (DWM). Fullscreen optimizations attempt to make the game appear exclusive, but in reality, it's handled in a way closer to... modern frameless windowThis allows Windows to insert intermediate layers and better manage things like the game bar, notifications, overlays, and fast switching between applications.

The problem is that, in practice, That extra layer can interfere with the GPU's rendering flowespecially when multiple overlays come into play: Steam's, NVIDIA/AMD's, tools like MSI Afterburner, the Windows Game Bar, Discord, Razer Synapseetc. In certain games this translates into reduced GPU usage, increased CPU load, and micro-stuttering which are very annoying.

Relationship between Full Screen Optimizations, overlays, and GPU usage

Several players have shared very clear cases where the combination of “Full Screen Optimizations” enabled + Steam overlay turned on It significantly reduces performance. For example, in titles like Sons of the Forest or Call of Duty: Modern Warfare II, some users saw their GPU usage stuck at 60-70%, despite playing with Graphics settings on Ultra, no DLSS, 1440p, where normally the graphics card would be working almost at its maximum capacity.

After investigating, some came across a Microsoft technical article (from the DirectX developers blog) where it explains how the different overlays affect the rendering pipeline. By disabling fullscreen optimizations and checking the box of “Run this program as administrator” in the game executableThe GPU would automatically switch to a stable 99% usage, while the processor's load would decrease, making the game feel smoother.

The most revealing discovery came when examining the role of the Steam overlay. In one specific case, the player had changed the options directly in the I opened the game's EXE file and launched it from the installation folder.By doing so, the Steam overlay was not activated, and the game showed very high and stable GPU usage. However, when launching the same title from the Steam library with the overlay active, GPU utilization fell again to 70%.Disabling the Steam overlay and testing again from Steam restored GPU usage to 99%.

These repeated back-and-forth tests confirmed that it was not a simple placebo effect: the combination of Full Screen Optimizations and the Steam overlay It was measurably degrading performance in those specific games, cutting GPU efficiency by around 30%.

The role of DirectX 11, DirectX 12 and other APIs

A very important nuance is that Not all games are affected equally.Several users have pointed out that, in titles based on DirectX 12The setting to disable fullscreen optimizations has little to no impact or does nothing at all, since part of that management is integrated into the API itself and the pipeline is different from that of DX11.

In the case of Sons of the Forest, for example, it was initially assumed that the game used DX12 and therefore the change made no senseBut it was later clarified that this wasn't the case. Even so, the interaction between the game executable, the way it's launched (from Steam vs. directly), the Steam overlay, and Full Screen Optimizations itself remained the key to the problem. That is to say, The real importance of FSO depends on how the game is implemented and the graphics API it uses..

In older engines, DX11 games, or titles that aren't very well optimized, you're more likely to notice variations when changing this setting. However, in modern productions that make extensive use of DX12 or VulkanMany of the layers that Windows previously controlled globally are now managed within the game engine itself, so the impact of FSO can be minimal or nonexistent.

How to disable Full Screen Optimizations and test its impact

If you suspect that "Full Screen Optimizations" mode is affecting your game performance, the wisest course of action is to perform a controlled test on your own equipmentEvery PC and every game behaves differently, so there's no universal recipe, but these steps will serve as a guide.

1. Locate the game executable
Go to your game's installation folder (for example, through Steam by right-clicking > "Manage" > "Browse local files") and look for the main .exe file.

2. Open the compatibility properties
Right-click on the EXE file, go to "Properties," and then to the "Compatibility" tab. Here you will see, among other options, the option to “Disable fullscreen optimizations” and the "Run this program as administrator" checkbox.

3. Select or deselect the option and make comparisons
Enable “Disable fullscreen optimizations,” apply the changes, and launch the game. Then, repeat the same session with the box unchecked. Ideally, perform the test in an identical area of ​​the gamewith the same graphics settings, same resolution and same save point so that the results are comparable.

4. Monitor GPU and CPU usage
Use tools like MSI Afterburner, the Windows Game Bar performance monitor, or your GPU overlay to check graphics card utilization, CPU load, and FPSPay particular attention to whether the GPU usage hovers around 99% or falls significantly below that for no apparent reason when the game is demanding.

5. Repeat with and without overlays
To narrow down the cause, perform the same tests with the Steam overlay enabled and disabledAnd if you're using other overlays (NVIDIA GeForce Experience, Radeon Software, Discord, etc.), try temporarily disabling them as well. This will show you whether the bottleneck appears when FSO and overlays are used simultaneously, or if it remains the same.

The influence of overlays (Steam, Discord, Game Bar, etc.)

Overlaps have become ubiquitous: Steam overlay for achievements and chat, Windows game bar, GPU overlays, video recorders, and streamingEach one adds a small layer on top of the image generated by the game. When combined with Full Screen Optimizations mode, all of these layers can alter how the frames are displayed on the monitor.

In documented real-world cases, it has been observed that simply by disabling the Steam overlay A game like Sons of the Forest would go from approximately 70% GPU usage to stuck at 99%. This means that, even without changing the graphics settings or resolution, the game was being throttled by the interplay between overlay and screen mode.

This ties in with the technical explanation Microsoft gave on its DirectX blog: Each overlay must be integrated into the rendering pipeline.And the way Full Screen Optimizations merges the game's presentation with the desktop means that this process isn't always neutral. Sometimes the penalty is minimal, but in other configurations it can introduce extra latency, CPU and GPU desynchronization, or even FPS drops.

The practical recommendation is simple: if you notice that a certain game is performing far below expectations, Temporarily disable all overlays and check for changes.It's a quick test that can save you a lot of trouble, and if you identify a problematic overlay, you can leave it turned off just for that title.

Exclusive fullscreen vs borderless window and the Factorio case

Another common question in the PC community is to what extent a game is using exclusive full screen or borderless windowIn the case of Factorio, for example, many players claim that the game works in a borderless window-like mode, even though it is visually perceived as a typical "full screen".

Having come from playing many AAA titles in true full-screen mode that look almost like a video, some users notice that Factorio It does not behave the same in terms of capture and recordingThey cannot find a clear setting in the game options to change the windowed mode, nor can they record it using the same methods they use for other exclusively full-screen games, which reinforces the idea that internally a borderless windowed approach is being used.

If you can't record Factorio like you do with other games, it's likely that the capture software is waiting for a exclusive mode that doesn't actually exist in that titleIn those cases, it's a good idea to resort to capture the window directly (in OBS, for example, using "Window Capture" or "Game Capture" adjusted to how Factorio is presented) and, if you wish, also try forcing or disabling full-screen optimizations from the executable properties.

To take screenshots, you always have the option of the classic Print Screen / Windows + Print Screen Windows' Snipping Tool or the game's own built-in features (if included) can be used. For titles that operate similarly to a borderless window, these methods usually work well, as the game is more directly integrated with the desktop.

Errors, removed content, and confusion on Steam

When searching for information on this topic in forums and communities like Steam, it's common to find deleted threads, unavailable content, and errors such as "this content does not exist"These types of messages usually indicate that the author deleted the post, that the moderators removed it, or that the URL you are trying to open no longer points to valid content.

This lack of continuity in the debates can fuel some confusion: many people read recommendations out of context (“always disable Full Screen Optimizations,” “never touch it,” etc.) without seeing the specific tests, hardware specifications, or the game they were originally referring to. It's important to keep in mind that Not all performance tips apply to all devices or all games..

Therefore, before accepting any trick you see on a forum, it's advisable to Try it yourself with objective dataIt monitors FPS, CPU and GPU usage, temperature, frame rates, and, ideally, saves screenshots or short reference videos. This will help you distinguish between real changes and mere subjective or placebo effects.

Placebo or real improvement? How to interpret your results

The question of whether the supposed benefits are actually true always arises when it comes to full-screen optimizations. real or product of the placebo effectSome users, not seeing significant changes or after conducting unsystematic tests, conclude that "it's useless." Others, when they notice a particularly smooth session, tend to attribute it to the last setting they adjusted, even though the cause may be something else.

To minimize that confusion, it is important that structure your tests methodicallyTry playing in the same area of ​​the map, with the same number of NPCs or events on screen, for several minutes, both with the option enabled and disabled. Repeat the process several times, on different days if possible, and note the average FPS and GPU/CPU usage results.

If you see that, in your tests, disabling Full Screen Optimizations The GPU usage systematically increases from 60-70% to 95-99%. With normal use, the CPU is less saturated, and there are no performance drops, it's difficult to attribute it solely to placebo. However, if the differences are minimal (for example, 2-3 FPS up or down within the normal range of variation), it may be irrelevant in your case and not worth forcing the change.

It is also relevant to consider that, based on what has been seen in games with DX12 and modern APIsHowever, the effect of this setting is sometimes very limited. In these titles, if your problem is a CPU bottleneck, poor engine optimization, or insufficient VRAM, disabling FSO isn't going to work miracles. Therefore, interpret this option as one more advanced setting in your toolboxnot as a universal magic solution.

With all of the above, it is clear that the “Full Screen Optimizations” mode is not simply a magic button to be activated or deactivated without thinking, but a Another piece in the PC performance puzzle This interacts with the game's graphics API, active overlays, windowed mode, and how Windows renders frames. Understanding how these elements combine, testing with data from your own hardware, and tweaking overlays and settings thoughtfully will allow you to get the most out of your games without falling for myths or miracle solutions that only work in third-party videos.