Diffusion models are a strong backbone for visual generation, but their inherently sequential denoising process leads to slow inference. Previous methods accelerate sampling by caching and reusing intermediate outputs based on feature distances between adjacent timesteps. However, existing caching strategies typically rely on raw feature differences that entangle content and noise. This design overlooks spectral evolution, where low-frequency structure appears early and high-frequency detail is refined later. We introduce Spectral-Evolution-Aware Cache (SeaCache), a training-free cache schedule that bases reuse decisions on a spectrally aligned representation. Through theoretical and empirical analysis, we derive a Spectral-Evolution-Aware (SEA) filter that preserves content-relevant components while suppressing noise. Employing SEA-filtered input features to estimate redundancy leads to dynamic schedules that adapt to content while respecting the spectral priors underlying the diffusion model. Extensive experiments on diverse visual generative models and the baselines show that SeaCache achieves state-of-the-art latency-quality trade-offs.
Figures & tables
Figure 1: Conceptual illustration and motivation of the proposed caching scheme (SeaCache) compared with previous caching schemes. The lower panel shows a denoising trajectory of a cat image where coarse low-frequency structure appears at early steps and fine high-frequency details emerge at later steps, illustrating the spectral evolution of iterative generative models. SeaCache applies a Spectral-Evolution-Aware (SEA) Filter to raw diffusion features so that the distance measure better captures timestep-aware spectral residuals between timesteps.
Figure 2: Latency-quality trade-off in oracle experiments. We compare cache decisions based on raw output differences and SEA-filtered output differences (Sec. 4.1 ) on FLUX [ 29 , 28 ] and Wan2.1 1.3B [ 63 ] . The refresh ratio is the fraction of timesteps that run a full denoiser evaluation instead of reusing cached features. For each criterion, PSNR is computed between the cached sample and the corresponding full timestep (no-cache) sample, averaged over each prompt set [ 49 , 23 ] . At matched refresh ratios, the filtered criterion consistently achieves higher PSNR with respect to the full-compute trajectory, validating the effectiveness of a spectrum-aware distance for cache scheduling.
Figure 3: Overview of SeaCache. Given input features It and It+1 , SeaCache first applies FFT, multiplies by the timestep-dependent SEA filters Gtnorm and Gt+1norm , and then applies iFFT to obtain spectral-evolution-aware features P(Gtnorm,It) and P(Gt+1norm,It+1) (Sec. 4.1 ). A spectrum-aware dynamic caching module (Sec. 4.2 ) measures the relative distance Δt between consecutive filtered features, accumulates it over timesteps, and either reuses the cached output or refreshes the denoiser when the threshold δ is exceeded. The underlying diffusion model remains unchanged, so SeaCache acts as a plug-and-play cache policy that replaces only the distance metric.
Figure 4: Visualization of timestep-dependent denoising filters. (a) Optimal linear denoising responses Gt(f) across timesteps, where early steps primarily pass low-frequencies and later steps gradually include higher frequencies, reflecting spectral evolution. (b) Corresponding normalized filters Gtnorm(f) with unit mean gain, which stabilize filtered feature energy across timesteps and are used as SEA filters for cache scheduling.
Figure 5: Relative ℓ1 across the generation process. Stepwise relative ℓ1 distances between consecutive timesteps for different feature choices, averaged over ten samples for each model. Input denotes distances on the timestep-modulated input features It . Output is the last block outputs Ot . SEA(Input) , SEA(Output) applies the SEA filter to the input and output features, respectively. Poly(Input) corresponds to the polynomial-fitted input distance which is designed to approximate output differences from input features. SEA-filtered inputs closely track SEA-filtered outputs across timesteps, whereas other inputs show weaker alignment.
Figure 6: Qualitative comparison of SeaCache and baselines on FLUX at refresh ratios of approximately 30% and 50% .
Figure 7: Qualitative comparison of text-to-video generative models at refresh ratios of approximately 30% and 50% .
Figure 8: Ablation on spectrum-aware filtering. Trade-offs for different cache metrics on FLUX and HunyuanVideo . Results are averaged over 200 prompts for FLUX and 20 randomly selected from VBench for HunyuanVideo , with the other settings fixed.
Figure 9: Plug-and-play adaptation to DiCache. PSNR-refresh ratio trade-off on FLUX when applying the SEA-based cache metric to DiCache [ 6 ] . “DiCache+Ours” denotes DiCache combined with our SEA filter, while “DiCache” uses the original metric.
Figure 10: Refresh pattern across timesteps on FLUX . Per-timestep refresh ratio at a 30% budget. (a) SeaCache automatically concentrates refreshes on early timesteps, whereas (b) TeaCache spreads refreshes more uniformly over the trajectory.
Model
SEA Filter (s)
Latency (s)
Overhead (%)
FLUX (2D FFT)
0.058
9.4
0.6
HunyuanVideo (3D FFT)
0.362
90.8
0.4
Table 5: Runtime overhead of SEA filtering per sample, averaged over 10 runs.
Resolution
SEA Filter (s)
Total Latency (s)
Overhead (%)
480p
0.668
161.5
0.41
720p
1.539
561.1
0.27
Table 6: Runtime overhead of SEA filtering per sample on Wan2.1-14B-T2V at different output resolutions.
Models
Subject Consistency
Background Consistency
Temporal Flickering
Motion Smoothness
Dynamic Degree
Aesthetic Quality
Imaging Quality
Object Class
TeaCache ( δ =0.12)
95.59%
95.99%
99.14%
98.77%
62.50%
60.92%
62.07%
86.31%
TaylorSeer ( S =2)
95.75%
96.20%
99.09%
98.83%
63.89%
60.93%
62.73%
83.47%
SeaCache ( δ =0.19)
95.77%
96.28%
99.15%
98.88%
62.50%
60.55%
62.01%
85.28%
TeaCache ( δ =0.2)
95.57%
96.04%
99.18%
98.76%
62.50%
60.28%
60.28%
86.47%
TaylorSeer ( S =3)
95.67%
96.18%
99.07%
98.86%
63.89%
60.64%
63.25%
82.20%
SeaCache ( δ =0.35)
95.78%
96.35%
99.20%
98.92%
61.11%
60.00%
61.02%
82.59%
Table 7: VBench metrics in HunyuanVideo .
Models
Subject Consistency
Background Consistency
Temporal Flickering
Motion Smoothness
Dynamic Degree
Aesthetic Quality
Imaging Quality
Object Class
TeaCache ( δ =0.09)
95.89%
97.09%
98.30%
97.37%
81.94%
62.48%
67.88%
80.46%
TaylorSeer ( S =2)
95.78%
96.90%
98.37%
97.47%
88.89%
62.14%
68.08%
82.75%
SeaCache ( δ =0.2)
95.96%
97.05%
98.20%
97.41%
84.72%
62.31%
68.01%
81.17%
TeaCache ( δ =0.15)
96.04%
97.02%
98.21%
97.35%
83.33%
62.25%
67.47%
80.22%
TaylorSeer ( S =3)
95.32%
96.54%
98.21%
97.48%
84.72%
60.85%
67.83%
78.32%
SeaCache ( δ =0.35)
96.03%
97.00%
98.12%
97.39%
81.94%
61.71%
67.66%
79.75%
Table 8: VBench metrics in Wan2.1 1.3B .
Method ( ≈50% )
Rank ↓
Method ( ≈30% )
Rank ↓
TeaCache ( δ =0.12)
2.03
TeaCache ( δ =0.20)
2.16
TaylorSeer ( S =2)
2.06
TaylorSeer ( S =3)
2.09
SeaCache ( δ =0.19)
1.91
SeaCache ( δ =0.35)
1.75
Table 9: Comparison of avg. rank on VBench in HunyuanVideo .
Method ( ≈50% )
Rank ↓
Method ( ≈30% )
Rank ↓
TeaCache ( δ =0.09)
2.13
TeaCache ( δ =0.15)
1.53
TaylorSeer ( S =2)
1.91
TaylorSeer ( S =3)
2.34
SeaCache ( δ =0.30)
1.97
SeaCache ( δ =0.35)
2.13
Table 10: Comparison of avg. rank on VBench in Wan2.1 1.3B .
HunyuanVideo
Wan2.1 1.3B
Method ( ≈50% )
Single-scale score ↑
Multi-scale score ↑
Method ( ≈50% )
Single-scale score ↑
Multi-scale score ↑
TeaCache ( δ =0.12)
2.72
2.76
TeaCache ( δ =0.09)
2.97
3.03
TaylorSeer ( S =2)
2.92
2.95
TaylorSeer ( S =2)
1.90
1.95
SeaCache ( δ =0.19)
3.98
3.99
SeaCache ( δ =0.30)
3.93
3.95
Method ( ≈30% )
Single-scale score ↑
Multi-scale score ↑
Method ( ≈30% )
Single-scale score ↑
Multi-scale score ↑
TeaCache ( δ =0.20)
2.11
2.16
TeaCache ( δ =0.15)
2.44
2.49
Table 11: CompressedVQA [ 60 ] scores on HunyuanVideo and Wan2.1 1.3B under single-scale and multi-scale settings.
Method
Refresh Ratio
PSNR
LPIPS
SSIM
Distillation (LightX2V [ 11 ] )
Vanilla
25% (4 steps)
11.444
0.475
0.405
TeaCache
25% (4 steps)
11.762
0.480
0.420
SeaCache
25% (4 steps)
11.926
0.465
0.432
Efficient Attn. (Jenga [ 75 ] )
Vanilla
50% (25 steps)
15.154
0.357
0.604
TeaCache
50% (25 steps)
19.463
0.191
0.744
SeaCache
48% (24 steps)
24.453
0.097
0.852
Table 12: Compatibility with fast inference works on Wan2.1-T2V: LightX2V [ 11 ] (14B, 16-step) and Jenga [ 75 ] (1.3B, 50-step), evaluated under comparable refresh ratio budgets.
Method
R.R.
PSNR ↑
LPIPS ↓
Method
R.R.
PSNR ↑
LPIPS ↓
FLUX.1-dev (50-step)
MagCache ( δ =0.04) [ 43 ]
52%
29.96
0.056
MagCache ( δ =0.15) [ 43 ]
34%
24.73
0.126
SeaCache ( δ =0.215)
52%
30.37
0.053
SeaCache ( δ =0.4)
34%
24.97
0.123
MagCache ( δ =0.07) [ 43 ]
44%
27.89
0.079
MagCache ( δ =0.35) [ 43 ]
28%
22.51
0.179
SeaCache ( δ =0.27)
44%
28.09
0.072
SeaCache ( δ =0.55)
28%
23.01
0.172
Wan2.1 1.3B T2V (50-step)
Table 13: Comparison with MagCache at matched refresh ratios (R.R.) by tuning the cache threshold δ . We report full-reference quality against the uncached outputs on FLUX.1-dev and Wan2.1 1.3B -T2V. SeaCache shows higher PSNR and lower LPIPS than MagCache [ 43 ] at the same refresh ratio.
Figure 11: Qualitative comparison between MagCache and SeaCache at matched refresh ratios on FLUX.1-dev and Wan2.1 1.3B T2V. At the same refresh ratio, SeaCache better preserves the uncached trajectory while reducing refresh operations.
Figure 12: Additional qualitative comparison of SeaCache and baselines on FLUX at refresh ratios of approximately 30% and 50% .
Figure 13: Additional T2V qualitative comparison of SeaCache and baselines at refresh ratios of approximately 30% and 50% .
Diffusion model caching reuses features, activations, or attention states across denoising steps to reduce inference cost while preserving output quality.
College of Computer Science and Artificial Intelligence, Fudan University · School of Data Science, Fudan University · 3Shanghai Key Laboratory of Intelligent Information Processing