Input lag in games: Reduce Input Lag in PC Games: Definitive Guide

Reduce Input Lag in PC Games: Definitive Guide

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We all know that PC games offer a myriad of customization options that aren’t found on traditional game consoles, allowing you to tweak the experience to your liking. Did you know it’s possible to change the latency of a PC game as well? Our last article explored console latency, explaining how your controller’s responsiveness is largely tied to the developer’s vision of their game. Due to PC being open architecture, it’s possible to tweak the latency of a PC game using a variety of options in your graphic card’s control panel, as well as third party programs.

A game that requires this level of tweaking is Ultra Street Fighter IV. The game was mainly designed for Nvidia architecture, which resulted in the PC, PlayStation 3, and arcade versions being similar to each other in terms of latency. However, the fighting game community started to notice that the Xbox 360 version of the game had lower input lag over other versions. I measured this difference in latency when I wrote my last article, and the difference is quite noticeable: the Xbox 360 version of USFIV averaged approximately 85ms of controller latency, whereas the PlayStation 3 version averaged approximately 107ms (check out our video game input lag database). While technically not “arcade perfect”, most players preferred the lower latency inherent within the Xbox 360 version, which may have been a result of it using an AMD-based GPU. For years, the PC version at stock settings felt very similar to the PlayStation 3 version, which I personally didn’t enjoy due to increased latency. It felt awkward and unnatural after playing on the Xbox 360 version for so long. However, after plenty of experimentation, it’s possible to match and/or exceed the speed of the Xbox 360 version! It’s important to note that all of the tweaks mentioned below can work on any current PC game, and not just Ultra Street Fighter IV. Experiment and see what feels best to you!

 

Display:	BenQ RL2755HM 60hz Gaming Monitor
Display (G-SYNC):	Acer XB240H 144hz G-SYNC Gaming Monitor
Display (FreeSync):	BenQ XL2730Z 144hz WQHD FreeSync Gaming Monitor
Operating System:	Windows 8.1 64-bit
Motherboard:	MSI Z77A-GD65
Processor:	Intel Core i5 3570K Ivy-Bridge Quad Core
Graphics Card (Nvidia):	EVGA GeForce GTX 970 Superclocked (2)
Graphics Card (AMD)	ASUS Radeon R7 260X OC (2)
RAM:	4x4GB Samsung DDR3-1600 MV-3V4G3
Hard Drives:	Crucial M4 128GB SSD, Western Digital Caviar Black 2TB
Keyboard:	Ducky Shine 4
Camera:	Casio Exilim EX-ZR800
Nvidia GeForce Driver:	350.12
AMD Radeon Driver:	15. 4 (Beta)
Third-Party Programs:	D3DOverrider, RadeonPro

 

 

Input lag in video games is a result of two main things: frame rate and V-Sync implementation. On consoles, it usually isn’t possible to customize these options, resulting in a static controller response that is set forth by the developer. PC gaming doesn’t adhere to this restriction. In the following examples, Ultra Street Fighter IV is utilized as our preferred testing benchmark. Latency is measured after applying various configurations detailed in this article. Ultra Street Fighter IV is capped at 60 frames per second, so we utilize our Casio Exilim EX-ZR800 to capture footage at 120 frames per second. Our Ducky Shine 4 keyboard features a lighting mode that illuminates on each key press. To measure latency, we calculate the amount of frames between the first key press and the first action on-screen. The average of ten button presses is used as our final result.

 

• V-Sync OFF:

To achieve the lowest possible controller latency, the best option is to completely disable vertical sync. V-Sync is a function that allows the game to synchronize it’s frame rate with the refresh rate of the display. Disabling it removes the frame rate cap, which also causes massive amounts of screen tearing. The screen tearing exhibited by the lack of V-Sync can be very distracting to most gamers. If reducing input lag is your primary concern, then this is your best option. Ultra Street Fighter IV achieves an ultra-low 59ms (3.6 frames) of controller latency with all V-Sync options disabled on our Nvidia GPU, and 61ms (3.7 frames) of controller latency on our AMD Radeon GPU.

 

• In-Game V-Sync:

Every PC game on the market comes shipped with it’s own V-Sync option that can be toggled in the configuration menu of the game itself. Most of the time, this is the only option you’ll need for a smooth experience. However, it may not be the option with the lowest input lag. The stock V-Sync option in Ultra Street Fighter IV provides a base latency of 103ms (6.2 frames) of input lag, which is very similar to the PlayStation 3 version that measured 107ms (6.4 frames). Enabling V-Sync synchronizes the game with the refresh rate of the display to remove screen tearing, however it also adds around 2 frames of input lag in most cases. Enabling V-Sync in-game results in a controller latency of 103ms (6.2 frames) on our Nvidia GPU, and 102ms (6.1 frames) on our AMD Radeon GPU. In-game V-Sync under CrossFireX resulted in 103ms (6.2 frames) of input lag, though make sure frame pacing is set to ON within Catalyst Control Center. Disabling frame pacing results in an extremely high input lag of 143ms (8.6 frames), so you definitely want to avoid that scenario!

 

 

If a game suffers from poor V-Sync implementation, it is possible to force V-Sync through the GPU control panel itself, which may sometimes offer a better experience. Both Nvidia and AMD allow forced V-Sync via control panel, however only Nvidia’s forced V-Sync option worked in Ultra Street Fighter IV. The game presents slightly higher controller latency when forcing V-Sync via the control panel, with a controller latency of 109ms (6.6 frames). Forcing V-Sync on our GTX 970 SLI setup increased input lag over a singular GPU, bringing the latency up to 114ms (6.9 frames) However, it is possible to reduce latency further by configuring maximum pre-rendered frames (explained below).

 

This setting is buried under the “Manage 3D Settings” page in the Nvidia control panel. Maximum pre-rendered frames is a setting that governs the amount of frames the CPU is able to process before handing it off to the GPU. The default value is set to 3, which typically achieves the best balance between input lag and a smooth image. If you have a particularly powerful GPU, you can reduce this value in order to achieve significantly lower input lag, without any noticeable downsides. Setting it to 1 prevents the CPU from processing more frames than it needs to, allowing the GPU to do most of the grunt work. In Ultra Street Fighter IV, combining control panel V-Sync with a maximum pre-rendered frames (1) setting results in 95ms (5.7 frames) of controller latency, whereas keeping in-game V-Sync enabled with the maximum pre-rendered frames (1) setting resulted in 101ms (6.1 frames) of controller latency. On AMD Radeon GPUs, this setting is known as flip queue. You can configure this option by downloading the RadeonPro application, which allows deeper tweaking of your Radeon GPU. Forcing a flip queue setting of 1 resulted in an average input lag of 97ms (5.8 frames). Both AMD Catalyst Control Center and RadeonPro were unable to force V-Sync in Ultra Street Fighter IV. In-game V-Sync was used along with flip queue (1) setting within RadeonPro in order to achieve lower input lag for our Radeon GPU.

 

Click to enlarge picture

 

The Smooth V-Sync option is largely overlooked since Nvidia introduced it in 2013, though its importance in a multi-GPU setup shouldn’t be underestimated. Smooth V-Sync attempts to keep the frame rate at the most sustainable level. If your game constantly fluctuates between 30 and 60 FPS, there is a good chance that enabling Smooth V-Sync will lock you to 30 FPS throughout your gaming session, in order to provide the most consistent experience. There will be times where you will encounter an area of the game entirely in 30 FPS, then have it switch back to a higher frame rate when nothing is taxing your GPUs. The importance of Smooth V-Sync lies within games your SLI setup completely dominates. Ultra Street Fighter IV can be comfortably maxed out at 4K resolution on our singular GTX 970, so why bother enabling a secondary GPU? Because Smooth V-Sync allows for dramatic input lag reduction! Running Ultra Street Fighter IV on our Nvidia GTX 970 SLI setup with Smooth V-Sync active resulted in an average input latency of 87ms (5.2 frames), offering the lowest amount of input lag when compared to every other Nvidia V-Sync solution (with the exception of V-Sync OFF and G-SYNC).

 

 

• Windowed V-Sync:

It is possible to completely bypass control panel and in-game V-Sync options to utilize Windows’ native V-Sync implementation, which is also triple-buffered. By running the game in a window or borderless window, Windows handles the vertical synchronization, which can lead to smoother gameplay and lower input lag. Make sure you disable V-Sync in all other areas before doing so. Running Ultra Street Fighter IV in a window reduces input lag over both in-game and stock control panel V-Sync, with a controller latency of 98ms (5.9 frames) on our Nvidia GPU, significantly higher than AMD Radeon’s 81ms (4.9 frames) of latency under the same scenario. It’s also possible to utilize windowed V-Sync in both SLI and CrossFireX setups. On Nvidia’s SLI setup, we measured 95ms (5.7 frames) of controller latency, which is still higher than CrossFireX’s measured latency of 87ms (5.2 frames). Utilizing Windows’ built in V-Sync may not always be smooth sailing however, and can sometimes cause stuttering that is absent when running the game in fullscreen mode.

 

• Direct3D Overrider:

Direct3D Overrider is a popular application that has been used for many years as a way to force V-Sync and triple buffering into DirectX games. Games that tend to fluctuate frame rates with standard V-Sync can appear much smoother when allowing Direct3D Overrider to handle this task. Ultra Street Fighter IV presented varying results depending on which modes were utilized. Using only Direct3D Overrider’s V-Sync option resulted in 115ms (6.9 frames) of latency on our Nvidia GPU, and 106ms (6.4 frames) on our Radeon GPU. Enabling triple buffering on top of Direct3D Overrider’s V-Sync resulted in 120ms (7.2 frames) of latency on our Nvidia GPU, and 109ms (6.5 frames) on our Radeon GPU.

 

 

It gets even better. In 2013, Nvidia announced a complete V-Sync replacement known as G-SYNC. G-SYNC provides the benefits of V-Sync’s tear-free image, without the stuttering and input lag associated with traditional V-Sync. The technology allows the display to directly communicate with the GPU, bypassing the ruleset of traditional V-Sync entirely. Shortly after, AMD announced its own variable refresh rate technology known as Adaptive-Sync/FreeSync. The only catch to these technologies is the requirement of a newer display tailored for your specific GPU. I managed to test the benefits of both G-SYNC and Adaptive-Sync, and the results are simply incredible.

 

 

Bypassing all other forms of V-Sync, enabling G-SYNC within Nvidia’s control panel resulted in an enormous reduction of input lag. In most cases, connecting your Nvidia GeForce GPU to a G-SYNC monitor will automatically enable G-SYNC, though this setting can be enabled manually and tailored to specific games via the control panel. After connecting the GTX 970 to our Acer XB240H G-SYNC monitor, we measured a ridiculously-low input lag rating of 60ms (3.6 frames), which is essentially identical to V-Sync OFF! This is significantly lower than even the lowest recorded values from our V-Sync tests above. Nvidia also allows SLI users to partake in the G-SYNC ceremony. Running Ultra Street Fighter IV with G-SYNC active on our SLI setup resulted in a slightly higher latency measurement of 63ms (3.8 frames).

What if you bleed red? AMD Radeon users shouldn’t worry, as these benefits are present on FreeSync monitors as well! We hooked up our AMD Radeon GPU to our shiny new BenQ XL2730Z FreeSync monitor, and measured an equally-low 59ms (3.6 frames) of input lag with FreeSync enabled via Catalyst Control Center. Unfortunately, AMD doesn’t allow CrossFireX and FreeSync to be enabled together. AMD is scheduled to launch a driver update to enable this functionality in the future. This technology has proven to be a real game changer since its inception, and it’s great to see the benefits across a wide variety of games.

 

 

There are a few other methods that can reduce input lag within PC games. One of them involves using a frame limiter to set your maximum frames per second below the refresh rate of your display. You can cap your game at 59 frames per second on a 60hz monitor to reduce input lag considerably, however this will more than likely cause some stuttering in games that run best at a locked frame rate. Ultra Street Fighter IV requires a steady 60 FPS, and limiting it below this frame rate can cause some issues. Another way to reduce input latency is by enabling a higher refresh rate. While Ultra Street Fighter IV is capped at 60 FPS due to its gameplay mechanics, many other genres such as first person shooters are able to go above and beyond 60 FPS. Running a game at 120hz or 144hz can reduce input lag by over 50%, as long as your hardware is powerful enough to handle it! On top of reduced latency, motion will appear silky smooth, which can ruin your perception of 60hz if that’s all you’re used to!

 

Measurements below rounded up to nearest millisecond/frame. All measurements were calculated using Ultra Street Fighter IV as the preferred benchmark. Results may vary by game and hardware used.

Configuration	Latency (MS)	Latency (Frames)	Test Link
V-Sync OFF	59ms	3.5 frames	YouTube
G-SYNC	60ms	3.6 frames	YouTube
SLI + G-SYNC	63ms	3.8 frames	YouTube
Xbox 360 Version	85ms	5.1 frames	YouTube
SLI + Smooth V-Sync ON (Control Panel)	87ms	5.2 frames	YouTube
PlayStation 4 Version (1.03)	89ms	5.3 frames	YouTube
V-Sync (Control Panel) + Max Pre-Rendered Frames (1)	95ms	5.7 frames	YouTube
SLI + Windowed V-Sync	95ms	5. 7 frames	YouTube
Windowed V-Sync	98ms	5.9 frames	YouTube
V-Sync ON (Game) + Max Pre-Rendered Frames (1)	101ms	6.1 frames	YouTube
V-Sync ON (Game)	103ms	6.2 frames	YouTube
PlayStation 3 Version	107ms	6.4 frames	YouTube
V-Sync ON (Control Panel)	109ms	6.5 frames	YouTube
SLI + V-Sync ON (Control Panel)	114ms	6.8 frames	YouTube
V-Sync ON (D3DOverrider)	115ms	6.9 frames	YouTube
V-Sync ON + Triple Buffering (D3DOverrider)	120ms	7.2 frames	YouTube

 

Measurements below rounded up to nearest millisecond/frame. All measurements were calculated using Ultra Street Fighter IV as the preferred benchmark. Results may vary by game and hardware used.

Configuration	Latency (MS)	Latency (Frames)	Test Link
FreeSync (Adaptive-Sync)	59ms	3.5 frames	YouTube
V-Sync OFF	61ms	3.7 frames	YouTube
Windowed V-Sync	81ms	4.9 frames	YouTube
Xbox 360 Version	85ms	5.1 frames	YouTube
CrossFireX Frame Pacing OFF + Windowed V-Sync	87ms	5.2 frames	YouTube
CrossFireX Frame Pacing ON + Windowed V-Sync	88ms	5.3 frames	YouTube
PlayStation 4 Version (1.03)	89ms	5.3 frames	YouTube
V-Sync ON (Game) + Flip Queue (1)	97ms	5.8 frames	YouTube
V-Sync ON (Game)	102ms	6.1 frames	YouTube
CrossFireX Frame Pacing ON + V-Sync ON (Game)	103ms	6. 2 frames	YouTube
V-Sync ON (D3DOverrider)	106ms	6.4 frames	YouTube
PlayStation 3 Version	107ms	6.4 frames	YouTube
V-Sync ON + Triple Buffering (D3DOverrider)	109ms	6.5 frames	YouTube
CrossFireX Frame Pacing OFF + V-Sync ON (Game)	143ms	8.6 frames	YouTube

 

There are several ways to change the feel of your favorite PC game by employing the methods detailed above. While the results can vary by game, it is important to try these options if you are unsatisfied with the latency associated with default settings. One thing is clear, however: the absolute best way to reduce input latency while keeping a tear-free image is to acquire a G-SYNC or FreeSync display. For those on a budget, be sure to try the tweaks listed above and report your experiences in the comments below!

 

What is Input Lag & How Can You Fix/Test It?

There are many things that can ruin a gaming experience—low framerates, high network latency, a squeaky chair—but perhaps one of the most common (and most annoying) problems is input lag.

While input lag might not bother you if you’re sitting a few feet from your screen with a gamepad in hand, if you’re playing first person shooters with a mouse and keyboard, it can become a pain very quickly.

When you’re lining up the perfect headshot only to miss because the game registers your mouse click a second too late, input lag can mean the difference between winning and losing a match.

Perhaps even more frustratingly, there are several things that can cause input lag, making it hard to diagnose. But it’s possible to fix input lag and doing so doesn’t always have to cost an arm and a leg.

What is Input Lag?

Input lag, also known as ‘system latency’, refers to the time between your peripheral inputs and the corresponding game actions being outputted on-screen.

For instance, if you press your mouse button to make your in-game character shoot their weapon, input lag would be the time taken between the mouse press and your character visibly shooting on-screen.

Everyone has some level of input lag, it’s just that hopefully the latency is so low that it’s imperceptible. It occurs because there’s a whole chain of things that must happen between your mouse click and your character shooting their weapon.

1. First, your peripherals must process your input and send this data to your motherboard and then to your CPU.
2. Your CPU must then process this input and instruct the graphics card to render a certain game state based on this new information, which means transmitting the instruction via the motherboard to the graphics card.
3. Your GPU then needs to store the information in a render queue, render the new game frame, and send it to the display for output.
4. Finally, your monitor needs to display the new game frame on-screen, and it can only do this when the display ‘refreshes’.

All of these things happen between you pressing ‘shoot’ and your in-game character visibly shooting on-screen.

Any one of these steps can cause high input lag. Especially egregious input lag usually has peripherals or the monitor as the culprit, but GPU and CPU processing capabilities and the motherboard’s data transport capabilities can play a part.

Do you have Input Lag or Network Lag?

Sometimes network lag can be mistaken for input lag, and vice versa. Network lag is when data takes a long time to be sent or received over your network and the internet.

When gaming online, this might mean that your inputs take a while to translate into game actions, because there’s a delay between these inputs and the server registering and processing them or sending the resulting game state back to you for your PC to display.

Online games have some things happening ‘client side’ (on your end) and other things happening ‘server side’ (on the game server’s end). If the action you’re trying to perform is one that requires interaction with the server for it to register—say, opening a loot box that exists for everyone on the server—then network lag might be the culprit of any visible delay.

If you’re suffering from network lag, then likely only some game actions will be delayed. Maybe you’ll be able to move and shoot without any visible delay, but opening doors will be delayed. Or, as is most common with network lag, your gun will shoot with no delay but there will be delay between these shots and when they register as having hit the enemy.

If you’re suffering from input lag, on the other hand, every game action caused by an input from the peripheral in question will be delayed—for example, your character around, shooting, and interacting with in-game objects.

If you still can’t tell, online games should tell you your ‘ping’, which is how much network latency there is between your system and the game server. If your ping is high, the delay you see is most likely due to network latency, not input lag.

Also Read: What is A Good Internet Speed for Gaming?

What Causes Input Lag?

Input lag can be caused by any part of the chain leading from your key or mouse press to the corresponding game action being displayed on-screen. It’s most often caused by the peripherals or display, but it can also be caused by the CPU or GPU, or the transporting of data between all these things.

Mouse and Keyboard

If you have input lag, the culprit might be your mouse or keyboard. Apart from your monitor, your peripherals are most likely to be what’s causing delay.

Wireless mice and keyboards usually have more delay than wired mice and keyboards, but in recent years wireless technology has improved enough that the delay on the best wireless gaming mice like the Logitech G Pro X Superlight is imperceptible.

If you have an old wireless mouse or keyboard, or a cheap one that’s not designed for gaming, then this might be the cause of your input lag, because it can take a long time for inputs to travel wirelessly to your PC if the wireless technology in question isn’t very good.

But even some wired peripherals can suffer from input delay. One thing that can cause both wired and wireless mouse delay is a low polling rate, which is how many times per second your mouse communicates with your PC. Grabbing a gaming mouse capable of 1,000Hz polling should help eliminate input lag if your mouse is the culprit.

CPU

Inputs from your peripherals are sent via the motherboard to your CPU. Your CPU then takes these inputs and decides what to instruct your GPU to render.

For example, it might tell the graphics card to render the door opening. But the CPU’s processing might also involve other game changes—perhaps your ‘door opening’ stat simultaneously increases, for example. Once it’s computed what to do, it sends an instruction out to the GPU telling it what to process and render.

The longer it takes your CPU to compute all this, the longer the delay between your input and the corresponding game action being displayed on-screen.

However, even most budget gaming CPUs these days shouldn’t cause noticeable input lag in most games. But if your CPU is particularly slow, it might cause input lag in CPU-intensive games like simulation games or 4X games like Civilisation VI.

Graphics Card

After your CPU receives peripheral input data, it tells your GPU what new game state it should render based on this input. The GPU in your graphics card must then render this game state and send the render data out for your monitor to display.

The longer your graphics card takes to render each frame, the bigger the delay between your input and the corresponding game action being displayed on-screen.

As such, if your graphics card is slow—or if the game is poorly optimised for quick rendering—the more likely you are to suffer input lag because of this. In other words, higher FPS should reduce input lag, providing your monitor’s refresh rate is high enough to keep up with it.

Motherboard

Your peripherals’ inputs travel via USB to your motherboard, and then via your motherboard’s PCIe lanes to the CPU and graphics card, so if your motherboard is particularly slow at transmitting data this can cause input lag.

While USB and PCIe lane generations can affect the speed of large data transfers—such as to and from SSDs—it’s unlikely to directly affect input latency. This is because mouse and keyboard inputs use such little data bandwidth that wider USB and PCIe bus bandwidths likely won’t speed up transfers. And USB 2.0 allows for over 1,000Hz polling, so polling frequency shouldn’t be an issue either.

The only way that a modern motherboard is likely to be the direct culprit of input lag is if it’s faulty—if it has a faulty USB port or PCIe lane, for instance.

If the motherboard isn’t faulty, it might still indirectly cause input lag, however, by bottlenecking the data transfer between the CPU and GPU. If your peripheral input data is bundled in with other game instructions, then a slower motherboard data bus (PCIe) speed might impact how long it takes this data to reach the GPU for rendering, thereby increasing input lag.

Monitor

Apart from your peripherals, your display is probably the most likely culprit of input lag. After your monitor receives render data from your GPU, it must turn this data into the visible pixels on your screen.

Your monitor displays a new frame with each ‘refresh cycle’, and how many cycles it performs per second is called its ‘refresh rate’. Many monitors still have a 60Hz refresh rate, but these days they are increasingly defaulting to 75Hz at the budget end, and extend all the way up to 360Hz at the high end. The higher your refresh rate, the less likely you are to suffer input lag.

Apart from its refresh rate, a monitor’s internal hardware can influence how much input delay you experience. How a monitor is built can affect its response time, for instance, which is how quickly your monitor can make pixels change from one colour to another.

Even if you have a high refresh rate, if your monitor’s response time is slow it can give the appearance of input lag, as it’ll take more time for your game state to visibly change because of the delay between pixels changing colour. This causes a ‘ghosting’ effect on-screen, but if it’s particularly bad it can feel akin to input lag.

Manufacturers usually list monitors’ response times on their spec sheets, but these can sometimes be deceptive. Nothing beats checking out reviews online for first-hand, practical analysis of a monitor’s response time.

Mouse and Keyboard Drivers

For your PC to use your peripherals correctly, effectively, and efficiently, it must use drivers. A driver is software that helps a component communicate and interact properly with your operating system and applications.

If you don’t have the correct drivers installed—for instance, your motherboard chipset and gaming mouse drivers—then your operating system might not make full and effective use of your peripherals, leading to input lag.

Driver conflicts can also cause input lag. If another driver is interfering with your gaming mouse’s driver, this can sometimes cause problems, including input lag.

VSync

VSync is a technology that you can enable in games to prevent screen tearing. Screen tearing occurs when your monitor’s refresh rate isn’t synced with your framerate, so it draws a new frame to the screen before finishing drawing the previous one. VSync eliminates this by limiting your framerate and ensuring it’s synced with your framerate.

But because it limits your framerate and prevents rendered frames from being drawn to your screen until the monitor has fully displayed the previous one, VSync can delay the time between when a frame is ready to be drawn and when the monitor draws it. This can increase overall system latency and cause input lag.

This is more of a problem with VSync than other technologies used to combat screen tearing. Gsync and FreeSync, for example, shouldn’t cause as much input delay as VSync, but not all monitors support these technologies.

Is there an Input Lag Test?

One way to test input lag is to point a high-speed camera at both your mouse and monitor, with an LED hooked up to your mouse button switch. This way, you can measure the video frames between your mouse press LED and your gun firing in game.

Another way is to use NVIDIA’s Latency Display Analysis Tool (LDAT), a piece of hardware that somewhat automates this process for you. You hook it up to your mouse switch and point the sensor towards the part of the screen that will display a muzzle flash when you shoot, then connect it to your PC via USB and run the LDAT software. Once you’ve done this, LDAT should tell you your latency when you shoot.

Finally, if you have a GSync monitor that supports it, you can use the monitor’s built in NVIDIA Reflex Latency Analyzer. Simply connect your monitor to your PC and connect your mouse to your monitor. Then, in your monitor’s settings, set the Analyzer’s analysis window to cover where your gun’s muzzle flash will appear. When you shoot, it should tell you your system delay.

While these latency tests aren’t the simplest to perform, you shouldn’t need to use them to diagnose bad input lag. If you’re suffering from bad input lag, you should be able to see and feel it while gaming.

How to Fix Input Lag

While fixing input lag might sometimes require upgrading your hardware—usually your peripherals or your monitor—there are often ways to fix it that don’t require spending any money.

1. Update and Reinstall your Drivers

If you have input lag, probably the first thing you should try is updating your drivers. Occasionally Windows or other updates can roll out that mess with mouse drivers, and manufacturers will scramble to create new drivers that fix these issues. So, keeping on top of your driver updates can sometimes resolve high input lag.

If just updating your drivers doesn’t solve it, you should try reinstalling all your drivers, ensuring that you only install drivers that you need. Sometimes input lag is caused by one driver conflicting with another—perhaps at some point you accidentally installed another mouse driver that you don’t need. Removing all your drivers and reinstalling only those that you need should fix this.

2. Disable VSync

If you play with VSync enabled in-game and you suffer from input lag, you should try disabling VSync to see if it resolves the issue.

VSync can cause input lag because, to fix screen tearing, it adds delay between your GPU rendering frames and these frames being displayed on the screen. If you have a GSync or FreeSync monitor, try enabling these instead of VSync.

If you don’t have a GSync or FreeSync monitor, you might have to choose between either no screen tearing and input lag, or screen tearing and no input lag. In my experience, however, screen tearing is far less annoying than input lag, so disabling VSync might be a good solution.

3. Enable NVIDIA Reflex or AMD Anti-Lag

One thing that can cause input lag is your GPU’s render queue, which is where your GPU stores instructions for what frames to render. The bigger the queue, the more frames it has waiting to render and the longer you have to wait before your input translates to on-screen action.

NVIDIA Reflex is a technology that attempts to reduce input lag by eliminating the render queue, allowing the GPU to render frames as soon as the CPU tells it to. NVIDIA GeForce GTX 900-series cards and above can use Reflex in supported games, and it can be enabled in these games’ settings menus.

If the game you’re playing doesn’t support NVIDIA Reflex, you can go to your NVIDIA control panel and toggle ‘Low Latency Mode’ to ‘Ultra’ under the ‘Manage 3D Settings’ tab. This attempts to eliminate the render queue on the driver (rather than game engine) level and should work almost as well as NVIDIA Reflex.

If you have an AMD card, you can enable AMD Anti-Lag for individual games via the Radeon control panel. This works in a similar way to NVIDIA’s Low Latency Mode, reducing the number of instructions queued and thereby reducing delay.

4. Cap your Framerate

Capping your framerate can reduce input lag in some games and some scenarios.

If your GPU is under 100% utilisation while gaming, capping your framerate to a little lower than your GPU is capable of outputting should reduce GPU load and allow it to process and render frames more quickly. If your GPU is handling things at lower than max utilisation, however, capping your FPS probably won’t reduce input delay very much.

Also bear in mind that setting your frame cap too low can have a negative impact on input latency. Lower FPS means more time between each frame being displayed on screen, which means more input lag.

Striking a balance between GPU utilisation (via an in-game frame cap) and a high framerate (by not capping your FPS too low) is key.

5. Lower your Graphics Settings

Providing it doesn’t max out your GPU utilisation, increasing your framerate should reduce input lag, because more frames being rendered each second means less potential time between each frame—and the game actions—being displayed on screen.

As such, lowering your game’s graphics settings—especially your resolution—can help increase your FPS and reduce input lag. If you don’t know which settings to change, you can check out some of our game settings guides, such as this one that shows you the best settings for Fortnite.

6. Try a Different USB Port

While it isn’t a likely cause, it could be that your input lag is being caused by a faulty or poorly performing USB port. If your USB port isn’t working as intended, it might be delaying the input from your peripheral to your system.

Try plugging your peripherals into different USB ports, preferably ones on the back of the tower, connecting directly to the motherboard, rather than via the tower’s front panel ports.

7. Upgrade your Hardware

If you’re still suffering from input lag and you’ve tried all the above, one of your components might be the culprit. Most likely, if your input delay is very noticeable, it will be a problem with your mouse or keyboard or your monitor.

If your monitor has a low refresh rate and a high response time, it could be this that’s causing delay. Consider choosing a monitor that’s known to have no latency issues and that has a high refresh rate.

If your monitor already has a low response time, high refresh rate, and tests well for latency in online reviews, then it’s more likely that your mouse or keyboard will be the culprit. Look for a mouse that’s known to have a great sensor, high polling, and, if it’s wireless, great wireless connectivity, such as via Logitech’s LIGHTSPEED technology.

Finally, while this is rarely the culprit, if you have exceptionally old and slow hardware—motherboard, CPU, GPU—then this could be causing input lag, as frames likely aren’t being churned out and drawn to the screen fast enough to keep up with your inputs. In which case, upgrading to any modern, midrange gaming CPU and GPU should improve your input latency.

Game Lag/Lag Reduction Guide

In this guide, we’ll show you how to get the most responsive gaming experience with NVIDIA Reflex technology, system profile and peripherals. Delays are system and network. The task of the gamer is to optimize the PC in such a way as to get rid of both «misfortunes». The procedure consists of several steps (peripheral delay, PC delay and display delay). Let’s talk about each in more detail.

How to optimize peripheral latency?

Mice and keyboards recognize and process clicks, mouse movements, etc. Different device models do this at different speeds. Much depends on the mechanical elements and methods of processing clicks, as well as on the frequency of polling the model.

First of all, you need to increase the polling frequency to the maximum (the ceiling is usually 1000 Hz). Higher polling frequency means more actions per unit of time. A mouse with a polling rate of 125Hz creates system latency of up to 3ms compared to 1000Hz!

It is important to remember that sensor sensitivity has almost no effect on latency. High DPI does not mean low latency.

The solution is obvious: you need to purchase a manipulator with a high polling rate.

How to optimize PC latency?

PC latency is directly related to OS, specific game and rendering process.

The following steps are recommended for optimization:

• enable NVIDIA Reflex Low Latency Mode if it is compatible with the game (supported by all GeForce graphics cards starting from the GTX 900 line)

• If the NVIDIA Reflex option is not available, you must enable Ultra Low Latency mode in the NVIDIA Control Panel (graphics driver)

• it is recommended to always play in Exclusive Fullscreen mode (or just Fullscreen), if this option is available

• disable vertical sync (VSYNC). This must be done not only in the NVIDIA control panel, but also in the game settings

• enable «Game Mode» in Windows, it will help allocate more system resources specifically for the game (activating the profile mode is easy, go to «Start», then to Settings, select Game Mode in the Games tab)
• it is recommended to overclock the CPU and GPU, overclocking will help reduce system latency by a few more milliseconds

How to optimize display delays?

This option can be «divided» into three main parts: scanning, processing and pixel response (Scanout, Display Processing and Pixel Response).

For profile optimization you need to follow these steps:

• enable the maximum refresh rate of the monitor (or buy a new display with support for higher rates), you can do this in the NVIDIA control panel

• If your monitor supports the G-SYNC Esports option, enable it too

Keywords: GeForce NVIDIA

Is cloud gaming doomed by physics? Or more about input lags, where they come from and how to deal with them — Gamedev on DTF

Input lag journey from cloud servers to user monitors.

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For many years, the computing power of a PC depended on the investment invested in it: the more expensive it was, the higher the performance it had, which means it could run more demanding games on hardware. But since the system requirements of games grow from year to year, such investments in hardware also depreciate quickly. Now, moreover, there is an iron deficiency at all, which does not get better, and when it is, it costs a lot, a lot.

But there is a solution. With cloud gaming, you don’t have to worry about how weak or powerful your PC is. You simply select a game from the service and launch it, and the commands from your controller are sent to the server, rendered in the game, converted into video and audio streams, and then transmitted back.

Seems like too many steps, long and complicated? Let’s figure it out.

Video quality and latency

When playing on PC and consoles, video artifacts in the image and input lag from pressing a button to executing a command on the screen are minimized. The quality of the video directly depends on the processing power of your hardware and the capabilities of the game engine. The delay depends mainly on the frame rate in the game, the way the game logic is processed by the engine, and the signal processing time by the monitor.

With this in mind, it’s not easy to determine the overall latency for all games and hardware configurations. However, for ease of comparison, we will make a few generalizations to better understand the difference between playing locally and playing in the cloud.

Local computer input delay

One of the main factors affecting latency is the number of frames per second at which the game is rendered. In the example below, we are using 60 FPS, at which each frame will be visible for 16.7ms. Please note that many modern games on consoles run at 30 FPS, which makes each frame visible for 33.3ms.

So what we see here:

• The user presses a button on the controller, after which a signal is sent to the console / PC. 10ms is a rough number, because the signal delay depends on many factors: the specific controller, whether it is wired or wireless, etc.
• Based on the received data, the game logic is first calculated and then transferred to the display. In an optimized game engine for modern games, this typically takes three frames.
• The average input delay for the display is about 30 ms. Not to be confused with display refresh rate or response time, which are always faster.

So your gaming device, whether PC or console, will take 90ms to update according to your input command. That’s 5 frames, or almost a tenth of a second.

Note that if we were rendering at 30 FPS, we would have to add another 50 ms, because then we see each frame for twice as long:

Cloud gaming input delay

Cloud gaming input lag is a different story as there are many more processes to consider. As the flowchart below shows, things are no longer so simple:

• As in a local game, everything starts with the user having to send an input command;
• It is received by the user’s gaming equipment (PC, console or mobile phone) and then transmitted to the cloud servers with the desired game. Note that this step will be faster when your controller is also a gaming device — as in the case of mobile phones. In this aspect, the experience of Stadia was quite interesting, the controller of which was directly connected to the router, bypassing the intermediate link — directly to the PC;
• The game engine receives an input command, after which the game logic is calculated and rendered;
• The rendered signal is passed to the encoder, which encodes the material into the appropriate audio and video codec, which is then passed back to the user;
• The received audio and video codec is decoded and rendered, and then transferred to the monitor;
• The monitor performs internal signal processing and displays the image on the screen.

If you add up all the components, the delay will be about 130 ms — or 180 ms in the case of 30 FPS, by analogy with the previous calculations.

Now let’s look at the results of the study, the authors of which state that the maximum interaction delay for many games should be no more than 200 ms, and for games that require fast response — no more than 100 ms.

Some specific scenarios:

• Shooters and fighting games should have less than 100ms latency as they are particularly responsive;
• Role-playing games such as World of Warcraft must have a latency of no more than 500ms. They are no longer as sensitive to reaction speed, but still require some responsiveness to the events of the game world and reliable performance of actions, such as healing a character or casting spells.
• RTS are even more lenient on latency and sometimes allow up to 1000ms. It is no longer so important for such players that all their actions are performed immediately. So, the construction of buildings can be done without a constant update of the game.

Taking this into account, it seems that the increase in latency by 1. 5 times compared to the local computer does not look critical. But why then is the first impression of cloud gaming usually negative?

Most of the time it’s the user’s Internet connection. And that your 100 Mbps is not necessarily 100 Mbps at all.

Next, we’ll look at what can prevent cloud gaming users from achieving optimal input latency.

From server to user

In general, Internet and IP routing by default do not guarantee reliable data delivery and quality of service. In addition, they have a number of other limitations that make it difficult to maintain a low ping all the time.

There are many ways in which a delay can occur. The small size of game packets—typically 55 bytes versus 1,500 for a standard Internet packet—results in IP routers reducing processing overhead by a factor of 27. A smaller packet size also results in more dropped packets, since buffer limits are usually set based on the number of packets, not the size.

Other latency issues arise from how IP networks calculate the routing of packets. The Internet’s primary routing protocol, BGP, can create ring paths over a network with more hops than necessary, and even create different paths for incoming and outgoing traffic. Also, when it comes to peering or forwarding traffic to other networks, BGP does not take into account the receiving network’s bandwidth, real-time performance, or network performance, and may choose different peering points for incoming and outgoing traffic. This can lead to very different performance results and low ping speeds — especially for gamers connected to networks of different providers.

Peering requires an understanding of end-to-end paths from the host server to the gamers who use it. Thus, real-time network analytics is required to provide the best gaming experience. By understanding game traffic patterns and how traffic flows across the Internet and other networks, game companies can optimize end-to-end traffic flows between their servers, content distribution networks (CDNs), the Internet, and end users.

Cloud gaming companies are increasingly building their own backbone networks to connect edge and core data centers that host game servers. This allows for more granular end-to-end control, providing the best performance for gaming applications. The Internet in this case acts for gamers only as a «last mile».

This data center interconnect structure typically consists of routers and fiber optic backbones. To ensure the determinism of these connections, it is necessary to coordinate the work of the IP and optical layers of the network. In modern software-defined networks (SDN), this role is performed by a central software controller. The system also has analytics built in, so unlike BGP, here we know the performance of the end-to-end route, including peering points, and routers and optical links are configured by the controller in accordance with specific performance policies and SLAs.

Internet connection speed

What happens to the signal along the way from the server to our homes, we have roughly figured it out. Let’s return now to more mundane things — to the Internet in our apartment.

So, indeed: the figure indicated in the service agreement is the maximum possible speed allocated by the operator to the channel. That is, it will be relevant for you if you are the only one using the Internet in the whole house, and there is no interference in the signal path. The situation seems pretty utopian, doesn’t it?

You can measure your actual Internet speed using, for example, speedtest.net. Try to find out the speed to Moscow or London — and count how many times there will be a discrepancy.

At the same time, the system requirements for an Internet connection, say, for GFN are from 15 Mbps for 720p at 60 FPS, from 25 Mbps for 1080p at 60 FPS, and for MY.GAMES Cloud — 10 Mbps for launch games in 720p at 30 FPS, 25 Mbps at 120 FPS.

In an ideal world where Internet speeds always meet our needs, an uncompressed signal at a high bit rate would be transmitted to the user, providing a super-quality image indistinguishable from that played back on local equipment. But due to bandwidth limitations around the world, the bitrate needs to be reduced while maintaining low latency and high video quality. As you probably already understood, this is not an easy task.

Keeping the minimum delay imposes restrictions on video streams. In such a case, B-frames cannot or should not be used, as the delay would then increase significantly. Other parts of the stream should be kept simple so that the encoder and decoder can encode and decode high frame rates and resolutions in near real time.

With these limits, increasing the bitrate solves the quality problem, but increases the delivery problem, since most homes around the world still do not have access to cheap, stable Internet connections that would have high bandwidth. And it’s not even about Full HD and 7-8 Mbps, but about 30+ Mbps — and this figure only increases with increasing frame rate and resolution.

Another way to solve the problem is to use a more efficient codec. Today, H. 264 is the most common codec: it is best used in cloud gaming services that do not depend on their own dedicated equipment for signal decoding. This is because most modern devices are equipped with chips capable of decoding certain H.264 profiles on the fly. However, if the user has a device with newer chips that support decoding of higher performance codecs (such as H.265 HEVC), the quality can be greatly improved using the same bandwidth.

From the same bandwidth requirements, one can guess that if the home Internet is not always suitable for playing through the cloud, then the mobile one, due to technical features, is not suitable at all. However, we are waiting for the spread of 5G — it is on it that a big calculation is made in improving the quality of cloud gaming.

Signal from router to PC

The Internet signal inevitably has losses, including on the «last mile» — already inside your apartment or house.

The best connection option, which removes some of the losses, is directly via an Ethernet cable to your computer, which you use alone. However, not all laptop models have such a connector at all, and in general, a WiFi router has long been a common solution for home and office, allowing you to connect to the same network from several devices and not get tangled in wires.

However, there are a few “buts” when using WiFi routers:

• As we have already said, the more people connect to the network, the slower the connection speed of a particular person will be.
• Most often, Internet routers operate at a frequency of 2.4 GHz — the same as Bluetooth devices such as computer mice and headsets, for example. Even an ordinary microwave has an effect on this frequency. The output can be a connection to WiFi at other frequencies — for example, 5 GHz. But not all devices support it, so you first need to make sure that both your PC and router can work with it.
• The signal from the router inevitably «goes out» when moving around the apartment and colliding with various obstacles: ceiling, walls, doors, furniture, especially iron. The signal will be much better if your PC is within the «line of sight» of the router.

Let’s now compare connection speeds via Ethernet cable:

AND wireless connection:

Ping increased a little, and the download speed fell — not critical, but noticeable.

If there are still problems on the PC

So, high ping and high latency are due to the poor quality of the connection between the PC and the game servers. And although some of the problems are solved only on the side of the Internet provider and the cloud gaming service, there are still some things that the user himself can do to make the game easier for himself.

So, if the connection leaves much to be desired, you can reboot the router or reconnect the cable through which you connect to the Internet. In the case of a router, it is also worth temporarily disconnecting other devices from the network: telephone, TV, smart appliances, as well as devices connected via Bluetooth. Finally, it is worth disabling file downloads, closing unnecessary tabs in the browser, and generally reducing the load on the operating system as much as possible, which can reduce network bandwidth — remember that all this “eats off” part of the speed from cloud gaming.

Reduced input lag can be partially eliminated by increasing the frame rate at which the game is running. Naturally, this will increase both the requirements for encoding and decoding the streams and the need for even higher bandwidth as more data needs to be transmitted.

Buying a monitor with faster signal processing or «game mode» will also reduce the problem by saving a few milliseconds of input lag. But keep in mind that «game mode» will reduce image quality, as signal processing will be done less often.

Instead of conclusion

So what about cloud gaming — is it really that bad with latency? It all depends on who you ask — but his future certainly looks promising, and here’s why.