NVIDIA DLSS 4.5 Dynamic Multi-Frame Generation and 6x Mode Officially Arrive

AVATARAT said:

OK.

Spoiler: Wall of text / The Technical Process

How Frames Are Generated (The Technical Process)​

When you play a game, the GPU and CPU work together to generate frames in a continuous loop. Here’s how it works step-by-step:

1. Game Engine Pipeline​

Every frame goes through a rendering pipeline in the game engine. The steps are:

1. Input Processing:
   • The CPU reads player inputs (keyboard, mouse, controller).
   • Example: Pressing the “W” key to move forward.
2. Game Logic Update:
   • The CPU updates the game world based on inputs.
   • Example: Moving the player character, updating AI behavior, or calculating physics (e.g., collisions, gravity).
3. Scene Preparation:
   • The CPU sends commands to the GPU about what needs to be rendered.
   • Example: “Draw the player character at position X, render the trees in the distance, and apply lighting.”
4. GPU Rendering:
   • The GPU renders the frameby:
     • Vertex Processing: Converting 3D models into 2D shapes.
     • Rasterization: Converting shapes into pixels.
     • Pixel Processing: Applying textures, lighting, shadows, and effects (e.g., reflections, anti-aliasing).
     • Output: Combining all elements into a final image.
5. Frame Display:
   • The rendered frame is sent to the monitor to be displayed.
   • The monitor refreshes at its refresh rate (e.g., 60Hz = 60 times per second).

2. Frame Time vs. FPS

• Frame Time: The time (in milliseconds) it takes to render one frame.
  • Formula:
    Frame Time (ms)=FPS1000
  • Example:
    • 60 FPS → Frame Time = 60 / 1000≈16.67 ms per frame.
    • 120 FPS → Frame Time = 120 / 1000≈8.33 ms per frame.
• FPS Calculation:
  • FPS is simply the inverse of frame time.
  • Formula:
    FPS=Frame Time (ms)1000
  • Example:
    • If a frame takes 8.33 ms to render, the FPS is 120.

3. What Happens When FPS Drops?

• If the GPU or CPU can’t keep up, frame times increase, and FPS drops.
• Example:
  • A frame takes 33.33 ms to render → FPS = 33.33 / 1000≈30 FPS.

4. Bottlenecks: Why FPS Isn’t Infinite
The FPS is limited by the slowest part of the rendering process:

• GPU Bottleneck: The GPU can’t render frames fast enough (common in high-resolution or graphically intense games).
• CPU Bottleneck: The CPU can’t prepare the scene fast enough (common in games with complex AI or physics).
• RAM/Storage Bottleneck: Not enough memory to load assets quickly (causes stuttering).
• Monitor Bottleneck: The monitor can’t display more than its refresh rate (e.g., 60Hz = max 60 FPS, even if the GPU renders 200 FPS).

5. VSync, FreeSync, and G-Sync
These technologies sync the GPU’s output with the monitor’s refresh rate to:

• Prevent screen tearing (when parts of the screen show different frames).
• Smooth out FPS fluctuations (e.g., if FPS drops below the monitor’s refresh rate).
• VSync: Syncs FPS to the monitor’s refresh rate (e.g., 60 FPS on a 60Hz monitor). Can cause input lag.
• FreeSync/G-Sync: Adaptive sync technologies that match the GPU’s FPS to the monitor’s refresh rate dynamically, reducing lag and stuttering.

Real-World Example: Generating 60 FPS
Let’s say you’re playing a game on a 60Hz monitor:

1. The game engine updates the world every 16.67 ms (CPU).
2. The GPU renders the frame in 16.67 ms.
3. The monitor displays the frame.
4. Result: 60 FPS.

If the GPU takes 20 ms to render a frame:

• FPS = 20 / 1000=50 FPS.
• The monitor will display 50 FPS, and you’ll experience stuttering if it drops further.

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When fake frames (also called interpolated frames or synthetic frames) are added to increase the perceived FPS, they are not rendered by the GPU like real frames. Instead, they are generated artificially using techniques like frame interpolation or upscaling. These fake frames are inserted between real frames to make motion appear smoother, even if the actual FPS is lower.


Here’s how they fit into the FPS formula and rendering pipeline:

1. How Fake Frames Are Generated
Fake frames are created using two main techniques:

A. Frame Interpolation (Motion Interpolation)
This technique generates new frames by analyzing motion between two real frames and creating intermediate frames.

How It Works:​

1. Two Real Frames are rendered by the GPU (e.g., Frame 1 and Frame 3).
2. Motion Analysis: The system analyzes the movement between Frame 1 and Frame 3.
3. Fake Frame Generation: A new frame (Frame 2) is created by blending or predicting the motion.
4. Insertion: The fake Frame 2 is inserted between the real frames.

Example:

• Real FPS: 30 FPS (33.33 ms per frame).
• With Frame Interpolation: 60 FPS (16.67 ms per frame).
  • The system generates one fake frame between every two real frames.

Technologies That Use This:

• NVIDIA’s Reflex + DLSS + Frame Generation (e.g., in supported games).
• AMD Fluid Motion Frames (FMF) (used in AMD GPUs).
• TV Motion Interpolation (e.g., “Motion Smoothing” on TVs).
• Intel XeSS Frame Generation.

B. Upscaling + Frame Generation (Hybrid Approach)
Some technologies combine upscaling (e.g., DLSS, FSR) with frame generation to boost both performance and smoothness.

How It Works:​

1. The GPU renders a frame at a lower resolution (e.g., 1440p).
2. The frame is upscaled to the target resolution (e.g., 4K) using AI (DLSS) or spatial upscaling (FSR).
3. Fake frames are generated to fill in gaps, increasing the perceived FPS.

Example:

• Real FPS: 45 FPS at 1440p.
• With Upscaling + Frame Generation: 90 FPS at 4K (perceived).
  • The upscaled frame is duplicated or interpolated to create fake frames.

Technologies That Use This:

• NVIDIA DLSS 3 (Frame Generation + DLSS Super Resolution).
• AMD FSR 3 (Frame Generation + FSR upscaling).

2. How Fake Frames Affect the FPS Formula​

The actual FPS (real frames rendered by the GPU) remains the same, but the perceived FPS (what the user sees) increases because of the added fake frames.

Formula Adjustment:
Perceived FPS=Real FPS×(1+Number of Fake Frames per Real Frame)

Examples:​

Real FPS	Fake Frames Added	Perceived FPS
30 FPS	1 fake frame	60 FPS
40 FPS	1 fake frame	80 FPS
60 FPS	0 fake frames	60 FPS

Key Differences:​

Aspect	Real Frames	Fake Frames
Source	Rendered by the GPU	Generated by software/hardware
Motion Accuracy	100% accurate	May introduce artifacts or “soap opera effect”
Input Lag	None	Can increase input lag
GPU Load	High (real rendering)	None (generated by dedicated hardware)
Perceived Smoothness	Smooth	Smoother (but not always better)

3. Where Fake Frames Fit in the Rendering Pipeline​

Here’s how fake frames are integrated into the traditional rendering pipeline:

1. Real Frame Rendering:
   • GPU renders Frame 1 (real).
   • GPU renders Frame 3 (real).
2. Frame Interpolation:
   • System generates Frame 2 (fake) by analyzing motion between Frame 1 and Frame 3.
3. Frame Insertion:
   • The sequence becomes: Frame 1 → Frame 2 (fake) → Frame 3 → Frame 4 (fake) → …
4. Display:
   • The monitor displays the sequence at a higher perceived FPS.

Visual Representation:​

Time: 0ms 16.67ms 33.33ms 50ms
Real Frames: [Frame 1] [Frame 3] [Frame 5]
Fake Frames: [Frame 2] [Frame 4]
Perceived: [Frame 1] -> [Frame 2] -> [Frame 3] -> [Frame 4] -> ...
FPS: 30 FPS (real) -> 60 FPS (perceived)

4. Pros and Cons of Fake Frames​

Pros:
Smoother Motion: Reduces stuttering and makes gameplay feel more fluid.
Higher Perceived FPS: Improves the gaming experience without requiring more GPU power.
Better for High Refresh Rate Monitors: Useful for 120Hz+ displays where real FPS might not reach the monitor’s limit.

Cons:​

Artifacts: Can introduce visual glitches, ghosting, or the “soap opera effect” (unnaturally smooth motion).
Input Lag: Adding fake frames can increase latency, which is bad for competitive gaming.
Not True Performance: Doesn’t actually improve the game’s real performance (e.g., physics, AI, or loading times).
Hardware Dependency: Requires specific hardware (e.g., NVIDIA RTX 40-series for DLSS 3, AMD RX 7000 for FSR 3).

5. When Should You Use Fake Frames?​

Use Case	Recommended?	Why?
Single-player games	Yes	Smoother visuals improve immersion.
Competitive gaming	No	Input lag can hurt performance.
High refresh rate (120Hz+)	Yes	Helps reach the monitor’s refresh rate even if real FPS is lower.
Low-end hardware	Yes	Boosts perceived performance without overloading the GPU.
Cinematic experience	Maybe	Can make games look too smooth (like a soap opera).

6. Technologies That Use Fake Frames​

Technology	Developer	How It Works	Hardware Required
DLSS 3 (Frame Generation)	NVIDIA	AI-generated fake frames + DLSS upscaling	NVIDIA RTX 40-series GPUs
FSR 3 (Frame Generation)	AMD	Spatial upscaling + frame interpolation	AMD RX 7000, RX 6000 (with update)
Intel XeSS Frame Generation	Intel	AI upscaling + frame interpolation	Intel Arc GPUs
NVIDIA Reflex + DLSS	NVIDIA	Low-latency rendering + upscaling	NVIDIA RTX GPUs
AMD Fluid Motion Frames	AMD	Frame interpolation (no upscaling)	AMD RX 7000 GPUs
TV Motion Interpolation	TV Manufacturers	Frame interpolation for movies/TV shows	Modern TVs

7. Summary: How Fake Frames Affect FPS​

1. Real FPS = Actual frames rendered by the GPU.
2. Fake Frames = Artificially generated frames inserted between real frames.
3. Perceived FPS= Real FPS + (Real FPS × Number of Fake Frames).
   • Example: 30 real FPS + 30 fake frames = 60 perceived FPS.
4. Trade-offs: Smoother motion vs. potential artifacts and input lag.
5. Use Cases: Best for single-player, immersive gaming, or high-refresh-rate monitors. Avoid for competitive gaming.

Final Answer:​

Fake frames are not part of the traditional FPS formula because they aren’t rendered by the GPU. Instead, they are inserted between real frames to increase the perceived FPS (what the user sees). The formula adjusts as:

Perceived FPS=Real FPS×(1+Fake Frames per Real Frame)

While this makes motion smoother, it doesn’t improve the game’s real performance and can introduce visual artifacts or input lag. Technologies like DLSS 3, FSR 3, and AMD FMF use this technique to boost perceived smoothness without requiring more GPU power.

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Mazzspeed said:

I know how additional frames are generated. Doesn't change the fact the smoother frames result from a boost in FPS assuming base FPS is adequate considering FG overheads, pushed by the CPU or not. I've covered latency as well as artifacting. With respect, I'm not going to keep arguing with people committed to misunderstanding my replies.

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AVATARAT said:

No, there’s no dispute, we just don’t agree with the word “boost” that you’re using; we’re all talking about the same thing and we all understand it the same way

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Mazzspeed said:

If you increase fps, it's a boost in fps. Smoothness results from that boost in fps regarding high refresh rate monitors. There's really nothing to argue.

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AVATARAT said:

If you have 60Hz monitor, and you already have 60 FPS, and you use FG to go for 120 FPS - then you will get less real FPS and you will have regress instead of boost.
It can be boost only if your monitor can display them.
So, from a purely technical standpoint, the word “boost” isn’t accurate in every aspect.

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Mazzspeed said:

The graph clearly shows that with DLSS set to Quality and with FG 2x enabled, latency is 25ms at 193 fps - Which is 1ms higher than native.

As stated, playing Marvel Rivals, my latency with FG 2x enabled is lucky to crack 10ms. I can and will provide screenshots if needed, something Duke can't do.

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MaZa said:

You are not comparing apples to apples.

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MaZa said:

But still, the point is you are trading off the gained improved latency for increased smoothness.

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MaZa said:

Reflex is also not limited to FG although game developers sometimes hide it behind it that. You can have its gains at native rendering too.

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Mazzspeed said:

I've been specifically referencing high refresh rate monitors. However, your claims regarding 60Hz monitors and FG assuming you can already maintain higher than 60fps with FG disabled make no sense whatsoever. Whether you run a 120Hz monitor or a 60Hz monitor, assuming you can already maintain higher than 60fps with FG disabled, the end result will be essentially identical with the exception that the 120Hz monitor will look smoother due to the effects of fps boosting - but the 60Hz monitor will see no regressions as a result of more fps, inserted frames or not. You may see some tearing on the 60Hz monitor, but that's about the extent of it - and under Linux Wayland with mailbox presentation, even that's not really much of an issue.

I have 60Hz monitors here, I have 100 - 120Hz monitors here across multiple machines, FG renders fine on all of them.

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1. Frame Generation (FG) and Frame Insertion​

• If your GPU renders 60 FPS:
  Your monitor displays 60 unique frames per second. Frame generation is not needed and won’t activate.
• **If your GPU renders below 60 FPS (e.g., 30 FPS):
  Frame generation inserts fake frames to reach 60 FPS. For example:
  • Real frames: 30
  • Fake frames: 30
  • Total displayed: 60 (30 real, 30 fake)
• **If your GPU renders above 60 FPS (e.g., 90 FPS):
  Frame generation may not activate if your monitor is locked at 60Hz. However, if frame generation is forced, it could:
  • Insert fake frames to reach 120 FPS (if your monitor supports it).
  • Or, if your monitor is 60Hz, it will still only display 60 FPS, but the frame insertion process can worsen frame timing and introduce artifacts (e.g., stutter, ghosting).

• Frame Insertion Creates Fake Frames:
  The sequence becomes:
  Frame 1 (real) → Frame 2 (fake) → Frame 3 (real) → Frame 4 (fake) → …
  This does not improve real performance—it only tricks your eyes into perceiving smoother motion.
• Frame Timing Worsens:
  Even if the monitor shows 60 FPS, the actual frame delivery is uneven because fake frames are inserted. This can cause:
  • Micro-stutter (uneven frame pacing).
  • Increased input lag (if the system prioritizes frame generation over real rendering).
  • Artifacts (e.g., ghosting, blurring).
• No Real Performance Gain:
  Frame generation does not reduce GPU workload or improve FPS. It only fills gaps with interpolated frames, which can make motion appear smoother but does not improve real responsiveness.

AVATARAT said:

I just use 60Hz as example.

And no, if you use FG to achieve more than your monitor refresh the things are as follow:

1. Frame Generation (FG) and Frame Insertion​

Frame generation (e.g., NVIDIA’s Reflex + FG, AMD’s Fluid Motion Frames, or Intel’s XeSS Frame Generation) creates “fake” frames to increase perceived smoothness. However, this does not improve real performance or reduce input lag.
What Happens at 60Hz with Frame Generation?

• If your GPU renders 60 FPS:
  Your monitor displays 60 unique frames per second. Frame generation is not needed and won’t activate.
• **If your GPU renders below 60 FPS (e.g., 30 FPS):
  Frame generation inserts fake framesto reach 60 FPS. For example:
  • Real frames: 30
  • Fake frames: 30
  • Total displayed: 60 (30 real, 30 fake)
• **If your GPU renders above 60 FPS (e.g., 90 FPS):
  Frame generation may not activate if your monitor is locked at 60Hz. However, if frame generation is forced, it could:
  • Insert fake frames to reach 120 FPS (if your monitor supports it).
  • Or, if your monitor is 60Hz, it will still only display 60 FPS, but the frame insertion process can worsen frame timing and introduce artifacts (e.g., stutter, ghosting).

2. The Problem with Forcing Frame Generation Beyond Your Monitor’s Refresh Rate

• Frame Insertion Creates Fake Frames:
  The sequence becomes:
  Frame 1 (real) → Frame 2 (fake) → Frame 3 (real) → Frame 4 (fake) → …
  This does not improve real performance—it only tricks your eyes into perceiving smoother motion.
• Frame Timing Worsens:
  Even if the monitor shows 60 FPS, the actual frame delivery is unevenbecause fake frames are inserted. This can cause:
  • Micro-stutter (uneven frame pacing).
  • Increased input lag (if the system prioritizes frame generation over real rendering).
  • Artifacts (e.g., ghosting, blurring).
• No Real Performance Gain:
  Frame generation does not reduce GPU workload or improve FPS. It only fills gaps with interpolated frames, which can make motion appear smoother but does not improve real responsiveness.

So, with Wayland, v-Sync is enabled (locked) by default, so in your (our) case, FG will activate when necessary, which is why it feels that way to you. But we’re talking about how things work by default for everyone.

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