Autoregressive (AR) video diffusion models enable streaming generation of long videos but suffer from significant memory overhead due to the rapidly growing KV cache. Existing KV cache quantization methods are primarily designed for LLMs and transfer poorly to video models, where activations exhibit different statistics and strong spatiotemporal redundancy. We observe that the video KV cache is largely predictable over time, with a clear asymmetry. Keys are highly predictable from their temporal history, while values depend primarily on the current key and need a short history of preceding values. Based on these observations, we propose \method, a training-free predictive KV cache quantization framework for AR video generation. \method predicts keys and values according to their distinct dependencies and stores only the residuals at low precision. Both predictors are lightweight, calibrated once offline by linear regression on a small set of BF16 samples, and remain fixed across prompts and generation runs. Experiments on Self-Forcing, Causal Forcing, and LongCat-Video-13B show that \method consistently achieves higher generation quality than existing KV cache quantization methods at comparable or higher compression ratios, reaching up to 6.71× KV cache compression with the best overall quality--efficiency tradeoff. Our code will be released on GitHub.
Figures & tables
Figure 1: Magnitudes of KV caches and their prediction residuals on Self-Forcing. Top: the original KV cache magnitudes at representative layers and heads. Bottom: the corresponding residual magnitudes after applying TempoKV. Prediction reduces the dynamic range of both keys and values, suppressing outliers across latent frames and channels.
Figure 2: TempoKV Framework. (a) Offline Calibration: a clean BF16 KV trace is collected from 8 calibration prompts, and predictors are fitted on it by linear regression. (b) Online Inference: Kt,s is predicted from the reconstructed K history, and Vt,s from the aligned Kt,s together with the reconstructed V history. Only the low-bit residual Rt,s is stored.
Figure 3: Asymmetric predictability of video KV cache. (a) Temporal history predicts keys well, while values benefit substantially from the aligned key. (b) This advantage holds across all layers. (c) The gain remains stable over long generation.
Figure 4: Qualitative comparison of long-horizon generation with Self-Forcing. While KIVI, QuaRot, and RTN exhibit progressively stronger visual degradation over time, TempoKV maintains greater temporal consistency, with results remaining close to the BF16 reference.
Method
Compression Ratio
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
Background Consistency ↑
Subject Consistency ↑
Dynamic Degree ↑
Imaging Quality ↑
Aesthetic Quality ↑
Motion Smoothness ↑
Visual Quality ↑
BF16
1.00 ×
∞
1.00
0.00
0.00
95.91
95.81
58.25
61.18
53.46
97.08
76.95
INT2 KV Cache, 480p
RTN
5.33 ×
10.32
0.42
0.58
143.05
95.76
95.05
15.05
42.05
41.22
96.73
64.31
KIVI
5.33 ×
10.57
0.33
0.66
168.80
95.29
95.09
12.43
42.75
43.03
97.43
64.34
QuaRot
5.33 ×
9.51
0.38
0.64
174.07
95.83
94.18
39.77
36.35
49.48
95.83
68.57
QVG
6.61 ×
16.21
0.70
0.22
14.24
95.99
95.78
54.62
58.58
52.42
97.47
75.81
Table 1: Causal Forcing results on MovieGen at 832×480 and 717 frames. Best and second-best results within each precision setting are shown in bold and underline , respectively.
Method
Compression Ratio
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
Background Consistency ↑
Subject Consistency ↑
Dynamic Degree ↑
Imaging Quality ↑
Aesthetic Quality ↑
Motion Smoothness ↑
Visual Quality ↑
BF16
1.00 ×
∞
1.00
0.00
0.00
96.36
97.88
42.39
70.39
39.77
98.61
74.23
INT2 KV Cache, 480p
RTN
5.33 ×
12.03
0.48
0.57
227.40
95.83
96.71
12.32
43.36
38.15
98.04
64.06
KIVI
5.31 ×
14.11
0.53
0.48
150.31
95.82
97.50
12.79
51.63
38.64
98.32
65.78
QuaRot
5.33 ×
11.68
0.34
0.60
139.98
89.07
78.92
36.34
62.76
38.57
96.12
66.96
QVG
6.61 ×
18.34
0.70
0.18
15.17
95.25
97.05
39.40
66.48
39.69
98.49
72.73
Table 2: Self-Forcing results on MovieGen at 832×480 and 717 frames. Best and second-best results within each precision setting are shown in bold and underline , respectively.
Method
Compression Ratio
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
Background Consistency ↑
Subject Consistency ↑
Dynamic Degree ↑
Imaging Quality ↑
Aesthetic Quality ↑
Motion Smoothness ↑
Visual Quality ↑
BF16
1.00 ×
∞
1.00
0.00
0.00
95.70
97.77
49.33
72.45
40.09
98.53
75.65
INT2 KV Cache, 480p
RTN
5.33 ×
14.21
0.57
0.36
96.48
95.73
97.55
30.20
56.86
38.46
97.60
69.40
KIVI
5.33 ×
15.33
0.63
0.34
62.02
94.96
94.39
30.67
64.07
38.84
96.63
69.93
QuaRot
5.33 ×
13.35
0.54
0.42
36.48
94.58
95.18
41.00
66.91
39.56
97.20
72.40
QVG
6.47 ×
15.75
0.66
0.25
24.29
95.61
97.66
47.33
69.54
39.95
98.52
74.77
Table 3: LongCat-Video-13B results on MovieGen at 832×480 and 717 frames. Best and second-best results within each precision setting are shown in bold and underline , respectively.
Figure 5: Quality–efficiency tradeoffs. Visual Quality is plotted against (a) peak VRAM, (b) KV-cache compression ratio, and (c) generation latency. TempoKV remains close to BF16 quality while providing the best balance among compression, runtime memory, and generation latency.
Figure 6: Quality preservation over long video generation. (a) Imaging Quality across increasing video lengths, where TempoKV remains close to the BF16 baseline and consistently outperforms existing quantization methods. (b–c) PSNR and SSIM comparisons further show that TempoKV better preserves quality under aggressive KV compression.
Figure 7: Predictor ablation. (a–b) Reconstruction error of the K and V caches on different effective bits. (c) Per-dimension difference between the cross predictor and the temporal-only predictor.
Table 11
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 8: Predictability of the key and value caches on LongCat-Video-13B, measured by cosine similarity between predicted and original caches. (a) Mean over all layers, with and without the aligned cache as input. (b) Per layer. (c) Per latent frame.
Bits (K/V)
Direction
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
2 / 2
K → V
19.85
0.7822
0.1303
10.04
V → K
17.66
0.6394
0.2575
75.73
4 / 2
K → V
23.17
0.8539
0.0729
5.23
V → K
17.71
0.6426
0.2562
73.80
5 / 3
K → V
24.17
0.8815
0.0597
4.13
V → K
20.74
0.7886
0.1139
17.24
Appendix
Table 6: Cross predictor is directional. Predicting V from the reconstructed K outperforms the reverse at every bit allocation and on every metric. The better direction is shown in bold .
Anchor bits
Comp. ↑
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
Subject
Motion
Aesthetic
Imaging
Consistency ↑
Smoothness ↑
Quality ↑
Quality ↑
2
6.739 ×
16.83
0.6095
0.2742
65.88
96.68
98.28
39.30
62.61
3
6.723 ×
19.53
0.7304
0.1471
23.31
96.96
98.43
39.69
67.35
4
6.707 ×
19.85
0.7832
0.1303
10.04
97.04
98.48
39.79
67.81
5
6.692 ×
19.79
0.7858
0.1243
10.09
97.04
98.49
39.83
68.02
6
6.676 ×
19.28
0.7818
0.1244
10.12
97.04
98.50
39.79
67.87
Appendix
Table 7: Ablation on anchor precision. Anchor precisions below 4 bits degrade reconstruction quality, whereas increasing the precision beyond 4 bits provides little additional benefit.
Method
Compression
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
Background Consistency ↑
Subject Consistency ↑
Dynamic Degree ↑
Imaging Quality ↑
Aesthetic Quality ↑
Motion Smoothness ↑
Visual Quality ↑
BF16
1.00 ×
∞
1.00
0.00
0.00
95.68
97.71
47.67
74.71
41.60
98.29
76.28
RTN
3.20 ×
15.65
0.72
0.17
15.23
95.28
97.61
43.12
74.33
40.59
98.32
74.87
KIVI
3.20 ×
13.13
0.61
0.32
59.83
95.60
94.81
26.67
65.02
39.14
96.39
69.61
QuaRot
3.20 ×
16.48
0.74
0.15
13.56
95.73
97.72
45.67
74.32
40.58
98.33
75.40
QVG
3.59 ×
15.43
0.66
0.23
18.94
95.58
97.51
47.00
74.32
40.60
98.18
75.53
QVG-Pro
2.75 ×
15.32
0.68
0.20
19.60
95.82
97.52
46.00
74.57
40.63
98.28
75.47
Appendix
Table 8: Quality comparison on LongCat-Video at 720p under INT4 quantization. Best and second-best results are shown in bold and underline , respectively.
Figure 9: Calibration of TempoKV. Left: A small calibration set is sufficient for TempoKV. Reconstruction error drops rapidly with the first few calibration prompts and nearly saturates thereafter on both Self-Forcing and Causal Forcing, with little additional gain beyond a handful of prompts. Right: TempoKV is robust to calibration-set distribution. Switching between action and scene prompts changes reconstruction error by at most 0.77% relative to the matched setting.
Method
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
Visual Quality ↑
Causal Forcing, 480p
Forcing-KV
9.32
0.38
0.58
40.07
76.70
TempoKV (k2v2)
17.23
0.76
0.17
9.15
77.04
TempoKV (k4v2)
22.85
0.79
0.13
6.34
77.11
TempoKV (k5v3)
23.21
0.80
0.11
4.03
77.12
Self-Forcing, 480p
Appendix
Table 9: Comparison with token pruning. Across both Causal Forcing and Self-Forcing, TempoKV improves fidelity in PSNR, SSIM, LPIPS, and FID, while also achieving higher overall Visual Quality.
Figure 10: Qualitative comparison on LongCat-Video-13B at INT4. TempoKV maintains superior temporal coherence and visual fidelity at a higher compression ratio.
Figure 11: Qualitative comparison on Causal Forcing at INT2. TempoKV maintains superior temporal coherence and visual fidelity at a higher compression ratio.