Every FPS Limiter Tested in Cyberpunk 2077: Nvidia Reflex vs RTSS vs Special K

Team Green's Reflex Low Latency combined with VSync and G-Sync delivers the lowest PC latency we measured—17.6ms in Cyberpunk 2077—but it comes at the cost of frame-time consistency. If smoothness is your priority, Special K's Latent Sync mode hit an adaptive STDDEV of just 2.4 FPS while keeping latency at a reasonable 20.8ms. And if you just want tear-free visuals without fuss, VSync still produces the flattest display times—though at a 52.1ms latency penalty that competitive players will feel immediately.

We tested ten popular framerate limiters using CapFrameX in a standardized Cyberpunk 2077 benchmark run, focusing on four key metrics: average FPS for raw performance, 1%/0.1% low average FPS and adaptive standard deviation for frametime consistency, and average PC latency for system responsiveness. Here's how each limiter performed—and when you should use it.

Framerate Limiters In Detail

When we talk about framerate limiters, we're talking about different mechanisms that interact with a game's rendering pipeline and your PC hardware in unique ways—each with different trade-offs for smoothness, input latency, and visual integrity. The following is a breakdown of each limiter we benchmarked in Cyberpunk 2077.

Vertical Synchronization (VSync)

VSync (vertical synchronization) forces a game's frame presentation rate to match your display's refresh rate. Its primary purpose is to eliminate screen tearing—the phenomenon that occurs when a new frame is sent to your display mid-refresh. VSync effectively makes your GPU "wait" for the next screen refresh before presenting a new frame.

How it affects game performance and presentation:

• No screen tearing: Keeps GPU frame presentation and display refresh rates in lockstep.
• Increased input latency: Because the GPU may have to wait for the next screen refresh, it adds delay between frame readiness and presentation—what gamers call "input lag".
• Stuttering at low FPS: If your framerate drops below the monitor's refresh rate, VSync can cause uneven frame pacing and stutter because it tries to maintain sync even when the GPU struggles.

When it's useful: VSync works best in single-player or cinematic contexts where tearing is distracting and input latency isn't critical. In variable refresh rate (VRR) setups (like Team Red's FreeSync or Team Green's G-SYNC), VSync can act as a backup to prevent screen tearing when framerate exceeds the VRR range on your display—though its latency penalty can be greatly mitigated when used with certain FPS limiters like NVIDIA Reflex Low Latency.

Pros/cons:

• Pros: Effectively eliminates screen tearing; provides visually calm, tear-free output; can help reduce minor visual artifacts when frametimes are stable.
• Cons: Introduces noticeable input lag; can cause stuttering/judder if framerate drops below refresh rate; caps framerate at refresh rate even when higher framerates would be possible—especially undesirable in competitive games.

In-game Framerate Limiter

Many modern games include a native option to cap the framerate directly within the game engine. This cap stops the game from rendering frames above your target, reducing system workload and preventing excessive production of unneeded extra frames.

How it works: Unlike VSync, an in-game engine FPS limiter simply waits after a frame finishes rendering before starting the next one, keeping frame pacing relatively consistent (if the implementation is good enough) without adding the same level of latency that synchronization to the display can introduce.

Pros/cons:

• Pros: Typically lower latency than driver or external caps; directly integrated in game engine logic and thus more convenient to use (when properly implemented).
• Cons: Quality and accuracy vary by game—built-in limiters can be coarse or inaccurate in some game engines.

NVIDIA Graphics Driver Framerate Limiter

Also known as "Max Frame Rate" in the NVIDIA Control Panel or the NVIDIA App, this limiter is part of Team Green's GPU driver and applies globally or per-application/game.

How it works: The GPU driver intercepts game engine rendering calls and enforces a ceiling on the framerate. It tends to be low latency and accurate enough for most use cases, though historically some older driver implementations didn't pace frames as smoothly as third-party tools—an issue that's largely been addressed in recent NVIDIA graphics driver versions.

Pros/cons:

• Pros: Easy to apply without external tools; often low overhead.
• Cons: Can sometimes produce less consistent frametimes compared to tools like RTSS in some titles.

NVIDIA Reflex Low Latency

Team Green's Reflex Low Latency is designed to significantly reduce system latency/input lag in games, making controls feel more responsive—especially in competitive titles—by synchronizing CPU and GPU work to eliminate render queue buildup. It works exclusively on NVIDIA GPUs starting from the "Maxwell" GTX 900 Series and up. Reflex Low Latency has its own framerate limiting algorithm, which works only when combined with VSync and G-Sync.

How it works: Reflex Low Latency integrates with the game engine (when supported) to complete rendering tasks just-in-time, minimizing the time frames spend queued to be rendered by the GPU before being displayed. It accomplishes this by aligning game engine work to complete just-in-time for rendering, eliminating the GPU render queue, and reducing CPU back pressure in GPU-intensive scenes. This reduces the delay between user input and visible result on screen—key to reducing what NVIDIA calls PC Latency, a metric that combines game latency, GPU rendering latency, and latency caused by other miscellaneous operations performed by your hardware during game rendering.

Interestingly, the Reflex Low Latency FPS cap—triggered when Reflex is used alongside VSync and G-Sync—has a formula that's been determined heuristically by the community:

Reflex LL FPS cap = Refresh Rate - (Refresh Rate * Refresh Rate / 4096 OR 3600)

So, for the most common display refresh rates, you are looking at the following framerate cap values:

Display refresh rate	60 Hz	120 Hz	144 Hz	180 Hz	240 Hz	360 Hz	480 Hz
Reflex LL FPS cap	~59 FPS	~116 FPS	~138 FPS	~171 FPS	~225 FPS	~328 FPS	~424 FPS

Pros/cons:

• Pros: Significantly lowers system latency/input lag compared to classic caps; designed specifically for maximizing gaming responsiveness.
• Cons: Only available in games that support it; effectiveness varies with game engine and GPU load; can sometimes cause additional frametime instability, which will hamper a game's visual smoothness.

RTSS FPS Limiters (Async, Front Edge Sync, Back Edge Sync)

RTSS (RivaTuner Statistics Server) is a third-party tool made by renowned Russian developer Alexey Nicolaychuk (AKA Unwinder) in collaboration with MSI. It has multiple useful functionalities—especially when used alongside MSI Afterburner (which Unwinder also made with MSI)—including the ability to cap game framerates externally to the game engine, not to mention setting up fancy performance overlays. It offers several framerate-limiting modes that affect how frames are paced:

Async (asynchronous): The default mode buffers one frame to produce extremely flat frametimes, which can feel very smooth visually. However, this buffer can add some extra latency, especially when having VSync enabled alongside it.

Front Edge Sync / Back Edge Sync: These modes sync frame presentation more carefully with the vertical blanking (VBlank) interval at either the front or back edge of the refresh period. They aim to improve timing precision and reduce screen tearing without a heavy latency penalty—effectively sitting between async's stable frame pacing and a minimalist limiter's responsiveness.

RTSS + NVIDIA Reflex: Interestingly, newer versions of RTSS can also use an internal Reflex Low Latency-style FPS limiter, which avoids the classic one-frame buffer and produces lower latency while still capping framerate.

Pros/cons:

• Pros: Very accurate and precise framerate caps; generally produces flatter, more consistent frame pacing; highly configurable limiter options.
• Cons: Async mode can sometimes introduce higher latency due to internal buffering; multiple modes can be confusing for users; real-world smoothness improvements may vary by game and engine.

Special K FPS Limiter

Special K is a powerful utility developed and maintained by renowned PC gaming modder Kaldaien. Special K isn't just an FPS limiter—it's a comprehensive performance and graphics enhancement framework that allows for many useful game tweaks. Its advanced frame pacing limiter targets smooth frametimes and timing consistency, while powerful graphics tech tweaks (including HDR tooling and NVIDIA DLSS/Microsoft DirectStorage tweaks), not to mention real-time latency/VRR analysis, make it a versatile tool well beyond simple framerate capping.

How it works: Rather than simply delaying between frames, Special K can intercept both before and after the frame's 'Present' call. It predicts rendering time and distributes idle CPU/GPU cycles to maintain smoother frame pacing, similar in effect to scanline-sync solutions but integrated deeply with the game engine. Special K also has the highly useful ability to inject Reflex Low Latency markers in certain games using modern graphics APIs (to show PC Latency numbers), and can even enable Reflex Low Latency itself in games that don't have official implementations.

In terms of framerate limiting, Special K has four modes that differ in how they handle latency vs frame pacing trade-offs:

• Normal mode: Geared towards providing an experience with minimal stuttering.
• Low-Latency: Ideal for displays that support Variable Refresh Rates; trades some frame pacing stability for even lower latency.
• Latent Sync: Ideal for fixed-refresh-rate displays that don't support VRR.
• NVIDIA Reflex: Mirrors the behavior of NVIDIA Reflex Low Latency; most suited for VRR displays and/or with DLSS Frame Generation/Multi-Frame Generation.

Pros/cons:

• Pros: Can deliver extremely consistent frametimes and very smooth output; has many advanced options for tuning a game's frame presentation model.
• Cons: Requires proper configuration per-game and sometimes troubleshooting—not as plug-and-play as in-game or graphics driver framerate limiters.

Technical Summary Table

Framerate Limiter	Target	Latency	Smoothness	Screen Tearing Protection
VSync	Sync to display refresh rate	Highest	Highest	Yes
In-game	Game engine-level cap	Very low	High	No
NVIDIA graphics driver Max Frame Rate option	GPU driver-level cap	Very low	Low	No
NVIDIA Reflex Low Latency + VSync/G-Sync	Works as an FPS cap with VSync/G-Sync	Lowest	Low	Yes (with VSync/G-Sync)
RTSS Async	External cap with a buffer	Very low	High	No
RTSS Front/Back Edge Sync	Sync-based caps	Very low	Moderate to High	No
Special K (Normal, Low-Latency and Latent Sync)	Engine/present-hooked cap	Very low	Lowest to Very High	No

All the aforementioned mechanisms aim to put a ceiling on rendering rates, but they interact with the game engine and display differently—which is why their effects on our chosen performance metrics (average FPS, 1%/0.1% low average FPS, adaptive standard deviation and average PC latency) vary. This is precisely why benchmarking them with a tool like CapFrameX yields insights that go beyond simple framerate numbers.

Testing Methodology

To ensure our benchmarking results are meaningful and reproducible, we standardized both our hardware/software setup and the performance metrics we collect. All benchmarks were run on the following system:

• CPU: Intel Core i7-14700K
• RAM: 32 GB DDR5-7000 CL34
• Storage: 2 TB PCIe 4.0 NVMe SSD
• GPU: NVIDIA GeForce RTX 4090
• Operating System: Windows 11 25H2
• All system firmware, drivers, BIOS, and OS updates were fully applied before testing.

We used CapFrameX's latest 1.8.1 build to capture and analyze raw frametime data during controlled runs of Cyberpunk 2077. For consistency, each test scene follows the same predetermined path while riding a bike through the same area so that rendering load and in-game events are as close to identical as possible. We enabled CapFrameX's run history and aggregation feature to record three independent runs of the same scene and aggregate the data—minimizing run-to-run variance and smoothing out transient noise.

All framerate limiter benchmarks targeted a 120 FPS limit, with the display refresh rate set to 120 Hz.

Average FPS

Average Frames Per Second (FPS) is the headline performance number most users know. It represents the total number of rendered frames divided by the capture time, giving a single figure that approximates the overall speed of the game rendering process during the benchmark session. However, average FPS alone can be misleading because it doesn't account for performance dips or the consistency of frame delivery.

1% Low Average FPS

The 1% low average FPS is the average framerate of the slowest 1% of all frames captured. This metric gives insight into the "worst sustained performance"—how low the framerate tends to dip during demanding moments of the scene. Higher values here (relative to average FPS) typically correlate with smoother overall gameplay and fewer perceptible stutters.

0.1% Low Average FPS

Even more extreme than the 1% low, the 0.1% low average FPS represents the average of the slowest 0.1% of frames. This metric highlights the most severe, albeit rare, performance drops that players are most likely to feel as stutters or hitches. Capturing this helps ensure we're not missing tiny but disruptive dips during heavy simulation or streaming spikes.

Average PC Latency

Average PC Latency measures the time (in milliseconds) between when a frame starts being rendered and when the completed frame is queued for display, approximating the system's internal latency. It focuses on how long it takes for your PC to process frames once input is received, excluding peripheral or display latency. The reason this metric matters is that in competitive gaming, input responsiveness matters as much as framerate.

Adaptive Standard Deviation (Adaptive STDDEV)

Adaptive STDDEV is an innovative statistical metric that CapFrameX uses to quantify how much the instantaneous performance values (e.g., frametimes converted to FPS) deviate from a moving average over time. Lower Adaptive STDDEV values indicate more consistent frame delivery with fewer sudden swings in frame timing—which usually translates to smoother perceived motion. In layman's terms, Adaptive STDDEV tells you how "jumpy" the performance feels over time: lower values mean your game runs more evenly, whereas higher values mean more noticeable bumps and irregularities in how frames are delivered. This makes it a valuable complement to percentile lows and averages when comparing FPS limiters' effectiveness in stabilizing performance.

Test Scene and Repeatability

For each limiter configuration, we ran CapFrameX captures over the exact same in-game sequence within Cyberpunk 2077. Instead of using a synthetic benchmark or a static scene, our choice of a bike-path run ensures repeated dynamic streaming of game assets and NPC interactions, better simulating real-world gameplay conditions. All graphics settings, resolution, and in-game options remained identical across runs and limiter types to ensure fair comparisons.

By using CapFrameX's run history average across three runs, we reduced anomalies caused by background Windows tasks, momentary hiccups, and other environmental noise. The aggregated data represent a more statistically robust picture of each limiter's performance profile than a single capture would.

Frametimes vs Display Times

It's important to note that all of our percentile-based FPS metrics—including 1% lows, 0.1% lows, and Adaptive STDDEV—are based on actual display times, enabled via CapFrameX's msBetweenDisplayChange option. This means the metrics are calculated from the intervals between frames as they actually appear on your monitor, not simply from when the game engine issues a frame to the graphics API. Using display-based timing better reflects what the player actually sees on screen, since it accounts for presentation timing and display refresh synchronization rather than just internal rendering calls. This approach produces more accurate and perceptually relevant measurements of smoothness and stutter compared to traditional frametime-only methods, especially when evaluating how consistent and fluid a limiter makes the experience feel with the naked eye. This approach also allows for more accurate measurements of smoothness with frame generation technologies enabled, but that is beyond the scope of this article.

Results and Analysis

Now for the raw benchmark captures of the Cyberpunk 2077 test sequence from CapFrameX's Analysis tab for each framerate limiter we tested. Each screenshot includes all key performance metrics—Average FPS, 1% and 0.1% low average FPS, Average PC Latency, and Adaptive STDDEV—so you can visually compare how different limiters behave in the same scene.

In the following captures, frametimes (which quantify visual smoothness at the PC hardware level) are displayed in blue, and display times (which determine visual smoothness at the display level) are displayed in green.

• VSync limiter:

Due to how it works, this limiter simply produces the smoothest display times—though it comes at a huge cost to average latency and responsiveness. Best used in single-player games (especially slow-paced ones) where latency isn't a critical concern.

• In-game limiter:

This limiter produced relatively smooth display times, and average latency was also quite low. It did produce screen tearing (even with VRR), though this can be mitigated by setting the cap below your monitor's max refresh rate. Best for casual gamers who want a decent set-and-forget FPS limiter.

• NVIDIA graphics driver limiter:

Team Green's driver limiter produced decently smooth display times—though not as smooth as the in-game limiter—with slightly lower average latency. Screen tearing was a concern, but can be mitigated by capping below your screen's max refresh rate. Best for casual gamers who want a global framerate limiter without third-party utilities.

• NVIDIA Reflex Low Latency + VSync/G-Sync limiter:

Team Green's Reflex Low Latency—when combined with VSync and G-Sync—produced the lowest average latency reading out of all tested limiters, which makes sense given its underlying mechanism. This did come at a cost of smoothness (indicated by a high adaptive STDDEV value), though VRR (G-Sync) greatly mitigates this drawback. Best combined with both VSync and G-Sync, and best used in competitive games where input latency is paramount. It's also a requirement for NVIDIA's AI frame interpolation technology (DLSS Frame Generation/Multi-Frame Generation) to work.

You may have noticed this limiter—when combined with VSync/G-Sync—results in a slightly lower average framerate than our 120 FPS target. Reflex Low Latency, when used with VSync/G-Sync, automatically paces frame delivery so that the framerate stays just below the display's maximum refresh rate—preventing VSync backpressure, keeping G-Sync engaged without tearing, and minimizing latency, effectively producing a cap of a few frames under the monitor's peak.

Note: NVIDIA Reflex Low Latency has an additional Boost mode that can further lower PC latency on the CPU side. We tested that mode as well, and in this case, it offered no meaningful differences in terms of both smoothness and average latency.

• RTSS Async limiter:

The RTSS Async limiter produced very respectable smoothness in terms of display time variability, and average latency was also quite low. Best for enthusiasts in games where both smoothness and latency are equally important (such as single-player shooters). Since it has no screen-tearing protection, set the cap slightly below your monitor's max refresh rate.

• RTSS Front Edge Sync limiter:

This limiter produced relatively smooth display times, though it also had quite a few lurches in both frametimes and display times. Average logged latency was quite low. Experiment with this limiter in various games and scenes to see if it provides tangible improvements over the default Async RTSS limiter.

• RTSS Back Edge Sync limiter:

Same behavior and recommendation as the RTSS Front Edge Sync limiter.

• Special K Normal limiter:

Despite a few frametime/display time excursions above the average, this limiter produced one of the smoothest display times overall—only tangibly beaten by VSync. Average latency was also decently low, though not as low as the highest-performing limiters. Best for tech-savvy enthusiasts in single-player games who are willing to spend extra time to get the most out of their hardware. Do not use this limiter (nor any other Special K limiter) in online games—anti-cheat software may flag Special K's game process hooking mechanism as a potential cheat.

• Special K Low-Latency limiter:

This limiter underperformed on display time smoothness, having the highest adaptive STDDEV value out of all tested limiters. Average latency was quite low, however. Best for advanced enthusiasts in single-player games that don't support any latency mitigation technologies. Again, don't use Special K's limiters in online games.

• Special K Latent Sync limiter:

This limiter produced the second-lowest adaptive STDDEV value out of all limiters—only beaten by VSync. It achieved this with much lower average latency than VSync, though it had screen tearing as well. Best for single-player games on fixed refresh rate displays, especially when the cap is set below the max display refresh rate. And again—don't use this limiter in online games due to anti-cheat concerns.

Given the results, it's clear that no single limiter is perfect—some favor tight, consistent frametimes or display times at the cost of latency, others favor responsiveness at the cost of microvariability. Which limiter is "best" depends on whether you prioritize smoothness, responsiveness, or a balance of both.

Below is a table summarizing all findings:

Limiter	Avg FPS	1% L	0.1% L	Avg PCL (ms)	Adaptive STDDEV	Smoothness	Latency	Recommended Use Case
VSync	119.9	118.8	118.2	52.1	0.3	Highest	Highest	Eliminate tearing
In-game	120	102.7	89.1	20	5.3	High	Low	Casual/stable + cap below refresh rate
NVIDIA driver Max Frame Rate	120	92.3	77.4	19	9.7	Low	Very Low	Balanced + cap below refresh rate
Reflex LL + VSync/G-Sync	116.1	88.4	74.7	17.6	9.6	Low	Lowest	Competitive/responsive/frame gen
RTSS Async	120	101.8	90.1	20.1	5.7	High	Low	Smoothness focus + cap below refresh rate
RTSS Front Edge Sync	120	96.7	75.8	20.6	4.6	High	Low	Smoothness focus + cap below refresh rate
RTSS Back Edge Sync	120	92.5	83.2	20.1	7.9	Moderate	Low	Smoothness focus + cap below refresh rate
Special K Normal	120	105.9	90.2	21.1	3	Very High	Low	Smoothness/consistency + cap below refresh rate
Special K Low-Latency	120	87.3	72.2	19.8	11	Lowest	Very Low	Low latency focus + cap below refresh rate
Special K Latent Sync	120	107.8	87.9	20.8	2.4	Very High	Low	Fixed-refresh rate + cap below refresh rate

Final Words

After running Cyberpunk 2077 through CapFrameX with multiple framerate limiting methods and examining not just average FPS but also 1%/0.1% low average FPS, adaptive standard deviation, and average PC latency, it's clear that every limiter carries its own set of trade-offs. Tools like RTSS (especially with its flat frametime pacing) and Special K tend to deliver very consistent frame delivery, reflected in low adaptive standard deviation values and stable frametime graphs—but this sometimes comes at the cost of slightly higher system latency due to internal buffering behaviors. Conversely, simpler caps such as the in-game limiter or Team Green's "Max Frame Rate" driver option typically produce lower latency and respectable stability, though they may not flatten frametimes as perfectly as RTSS or Special K. VSync—when used by itself—often adds noticeable latency and stutter/judder if your GPU can't keep up, making it less ideal unless combined smartly with an additional framerate cap and/or an adaptive sync/VRR solution.

Team Green's Reflex Low Latency stands out as a unique option: rather than enforcing a strict cap, it dynamically paces frame submission to minimize the render queue and therefore reduce latency, often keeping effective framerates just below your refresh boundary for a balanced experience. Reflex's dynamic behavior means that in many cases it lowers system latency more effectively than traditional caps, though this comes at the cost of frame-time consistency. This still makes Reflex Low Latency a compelling choice for responsiveness-focused players, especially in competitive/e-sports games that support the technology. By contrast, if your priority is absolute smoothness in frametime delivery—such as for cinematic single-player or capture scenarios—external limiters like RTSS or Special K's advanced limiter can yield flatter frame delivery graphs, even if the raw latency cost is a touch higher.

So which limiter should you use? If you're chasing the lowest possible input latency and your GPU is powerful enough, Reflex Low Latency—or Team Red and Team Blue's equivalent respective techs: Anti-Lag and Xe Low Latency—is typically the best everyday choice. For players who value visual smoothness and frame pacing consistency over split-millisecond latency differences, RTSS or Special K can be worth the added complexity. And for setups without adaptive sync/VRR support, pairing a well-chosen frame cap slightly below your display's refresh rate with your limiter of choice—whether in-game, driver, or third-party—gives you a solid balance of smoothness, low latency, and minimal screen tearing.

In short, the "best" limiter depends on your priorities: low latency for competitive play, or tight consistency for pleasing motion smoothness and stability. If adoption of latency-aware rendering technologies like Reflex continues at its current pace, we could see game engines prioritize these pipelines as standard—a shift that would benefit competitive gamers across the board.

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