Latency Test: Special K Latent Sync / RTSS Scanline Sync / G-SYNC / Low-Lag Vsync ON & Many More!

Summary

In this video, the presenter dives into an extensive analysis of latency in Hollow Knight, testing 50 sync scenarios using Intel PresentMon 2. The results, broken down into three charts, showcase various sync methods like Vsync, Fast Sync, G-SYNC, and Special K. Special K proves to be a powerful tool, outperforming traditional methods in certain cases, but caution is advised for multiplayer games due to potential bans. The video emphasizes the importance of optimizing settings for the best performance and invites viewers to experiment with different techniques for ideal results.

Takeaways

• 😀 Special K is highly effective in reducing latency, as evidenced by the testing results, but it has important limitations.
• 😀 A thorough latency test was conducted in *Hollow Knight*, using 50 different sync scenarios and 150 samples per scenario.
• 😀 Classic sync methods like Vsync and Fast Sync, with or without various frame rate limiters, offer varying levels of performance, with Fast Sync approaching the latency floor.
• 😀 Special K outperforms NVCP and RTSS, as well as the game’s internal optimizations, in reducing latency, particularly when using G-SYNC.
• 😀 Special K's “Normal” limiter shows higher-than-expected latency, which might indicate similarity to RTSS's “Front Edge Sync.”
• 😀 Low-Lag Vsync ON only offers latency reduction with a small FPS cap (-0.1), while Low-Lag Fast Sync always provides latency reduction.
• 😀 The latency difference between RTSS and Special K in Low-Lag Fast Sync is around 10ms, suggesting that Special K’s “Normal” limiter may align with RTSS's “Front Edge Sync.”
• 😀 RTSS's Scanline Sync variants, like “X2 Async” and “Back Edge Sync,” significantly reduce latency and double the frame rate.
• 😀 Special K allows users to fine-tune the “Delay Bias” between input and display latency, providing a unique way to optimize performance.
• 😀 Special K should not be used in multiplayer games, as it may lead to bans, a crucial warning for users considering its use in competitive play.

Q & A

What is the main goal of the video script?

The main goal of the video script is to compare various sync techniques and their impact on input latency in *Hollow Knight*, using Special K and other tools like RTSS and G-SYNC.

Why did the creator choose *Hollow Knight* for the latency tests instead of multiplayer games?

The creator chose *Hollow Knight* for the tests because Special K, unlike RTSS, may cause bans in multiplayer games. The tests are focused on single-player scenarios to avoid this issue.

What is Special K, and why is it highlighted in this video?

Special K is a software tool designed to reduce input latency and enhance gaming performance by modifying sync techniques. It is highlighted in the video because of its exceptional performance in reducing latency compared to other methods.

What are the three main sync methods discussed in the video?

The three main sync methods discussed are Classic Sync Methods (Vsync and Fast Sync), Low-Lag Sync methods, and Exotic Sync methods (like RTSS Scanline Sync and Special K's Latent Sync).

What is the significance of the latency floor and ceiling in the tests?

The latency floor and ceiling represent the best and worst-case scenarios for latency in the game. Vsync OFF gives the latency floor, while Vsync ON gives the ceiling, providing a baseline for comparison.

What conclusion did the creator draw from using Special K’s ‘Normal’ limiter?

The creator speculates that Special K’s ‘Normal’ limiter behaves similarly to RTSS's 'Front Edge Sync', though this is not confirmed. It was noted to cause higher-than-expected latency in some cases.

How does Fast Sync perform compared to other methods like Vsync and G-SYNC?

Fast Sync outperforms Vsync and G-SYNC by automatically capping the framerate at 600, which brings latency closer to the floor, offering smoother gameplay in *Hollow Knight*.

What does the second chart focus on, and what does it show about latency?

The second chart compares 'Low-Lag Vsync ON' and 'Low-Lag Fast Sync'. It shows that 'Low-Lag Fast Sync' consistently reduces latency, while 'Low-Lag Vsync ON' only reduces latency under specific conditions (e.g., with an FPS cap of -0.1).

What are RTSS Scanline Sync’s main characteristics in the tests?

RTSS Scanline Sync, particularly its 'Async' and 'Front Edge Sync' variants, resulted in higher latency, while 'X2 Async' and 'Back Edge Sync' showed a more significant reduction in latency, especially when doubling the framerate.

Why should Special K be avoided in multiplayer games?

Special K should be avoided in multiplayer games because using it can lead to bans. The tool modifies the game’s performance in ways that may be detected by anti-cheat systems.

What is the 'Big But' referred to at the beginning of the video?

The 'Big But' refers to the caution about using Special K in multiplayer games due to the risk of being banned, despite its benefits in single-player scenarios.