Organizations: State Key Laboratory of Virtual Reality Technology and Systems, Beihang University, Beijing, China · School of Computer Science and Engineering, Beihang University, Beijing, China · College of Information Technology, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates
Parameter-efficient transfer learning (PETL) has emerged as a pivotal paradigm for adapting pre-trained foundation models to downstream tasks, significantly reducing trainable parameters yet suffering from substantial memory overhead caused by gradient backpropagation during fine-tuning. While memory-efficient transfer learning (METL) circumvents this challenge by bypassing backbone gradient computation via lightweight small side networks, its stringent memory constraint severely limits learning capacity of side networks, thereby significantly compromising performance. To address these limitations, we propose a novel Mixed-Precision Interactive Side Mixture-of-Experts framework (MP-ISMoE). Specifically, we first propose a Gaussian Noise Perturbed Iterative Quantization (GNP-IQ) scheme to quantize weights into lower-bits while effectively decreasing quantization errors. By leveraging memory conserved from GNP-IQ, we subsequently employ Interactive Side Mixture-of-Experts (ISMoE) to scaling up side networks without sacrificing overall memory efficiency. Different from conventional mixture-of-experts, ISMoE learns to select optimal experts by interacting with salient features from frozen backbones, thus suppressing knowledge forgetting and boosting performance. Extensive experiments across diverse vision-language and language-only tasks demonstrate that MP-ISMoE remarkably promotes accuracy compared to state-of-the-art METL approaches, while maintaining comparable parameter and memory efficiency.
Figures & tables
Figure 1: Diagram on the proposed framework. Part (I) presents Mixed-Precision Interactive Side Mixture-of-Experts for universal METL based on side networks. We first quantize most of weights in pre-trained backbone before fine-tuning, while preserving trainable Layer Normalization with full-precision. Subsequently, we introduce a learnable parallel Interactive Side Mixture-of-Experts (ISMoE) structure, connected to backbone via downsampling module. During fine-tuning phase, Gaussian Noise Perturbed Iterative Quantization (GNP-IQ) strategy introduces Gaussian noise perturbations into weights to mitigate quantization error. Part (II) illustrates detailed structure of lth layer of MP-ISMoE. We adopt MoE to scale up side network, design representative feature for each expert to measure correlation with backbone, and select Topk experts based on the routing Probability and Correlation Score.
Method
Params.
Mem.
Flickr30K
MSCOCO1K
MSCOCO5K
Params.
Mem.
MSR-VTT
MSVD
(M) ↓
(G) ↓
I-T \!\uparrow\
T-I \!\uparrow\
Rsum \!\uparrow\
I-T \!\uparrow\
T-I \!\uparrow\
Rsum \!\uparrow\
I-T \!\uparrow\
T-I \!\uparrow\
Rsum \!\uparrow\
(M) ↓
(G) ↓
T-V \!\uparrow\
V-T \!\uparrow\
Rsum \!\uparrow\
T-V \!\uparrow\
V-T \!\uparrow\
Rsum \!\uparrow\
Fully-FT
201.2
176.8
85.6
73.3
546.6
83.1
71.7
542.7
64.2
51.2
468.9
151.3
48.8
42.8
42.1
389.2
45.2
57.1
425.5
LST
9.7
24.4
82.1
66.5
529.5
78.2
64.8
525.8
57.8
43.1
434.5
11.2
32.0
37.0
37.8
356.7
35.5
55.4
407.2
UniPT
12.4
24.4
84.8
69.1
537.4
80.6
67.5
532.9
61.1
45.9
445.3
9.6
13.6
38.9
39.3
361.3
40.9
59.7
432.1
SHERL
11.3
24.4
86.1
71.1
542.3
81.8
69.2
537.5
62.5
47.3
450.8
9.6
13.6
39.2
40.6
363.7
40.9
60.2
429.7
Ours †
12.9
25.5
86.5
71.3
543.1
81.9
69.1
538.7
62.2
47.1
449.1
10.1
14.5
39.9
41.1
365.5
42.0
60.4
435.6
Table 1: Comparison results (%) with METL approaches across various architectures and distinct VL tasks, in terms of amount of learnable parameters, memory usage, and other task-specific metrics. The best results are highlighted in bold , and the second best results are underlined .
Method
Params.
Memory ( G) ↓
CoLA
SST-2
MRPC
QQP
MNLI
QNLI
RTE
STS-B
Avg.
(%) ↓
Train
Test
Fully-FT
100
17.6
0.86
62.8
93.9
91.9
89.9
86.2
92.5
74.1
90.3
85.2
Adapter
1.63
13.0
0.87
64.4
94.2
88.9
88.9
86.4
93.1
75.1
91.1
85.3
LoRA
1.71
12.6
0.86
63.3
94.3
90.1
89.0
86.3
93.2
75.5
90.9
85.3
BitFit
0.13
10.7
0.86
61.8
94.3
91.0
88.7
85.6
93.1
67.6
90.8
84.1
Prompt
0.03
22.2
0.87
0
90.3
74.6
88.5
82.5
92.5
59.5
90.1
72.2
Table 2: Comparison results with PETL (Top) and METL (Bottom) methods on GLUE benchmark, with T5-base/large . We report the number of learnable parameters and memory usage as efficiency metrics, and accuracy, F1 score, Matthew’s Correlation, and Pearson-Spearman Correlation as performance indicators. The best results are highlighted in bold , and the second best results are underlined .
GNP-IQ
ISMoE
Params. (M) ↓
Memory (G) ↓
Flickr30K
MSCOCO1K
MSCOCO5K
I-T ↑
T-I ↑
Rsum ↑
I-T ↑
T-I ↑
Rsum ↑
I-T ↑
T-I ↑
Rsum ↑
12.4
24.4
84.8
69.1
537.4
80.6
67.5
532.9
61.1
45.9
445.3
✓
12.5
18.4
83.7
68.1
534.8
78.9
66.3
530.4
59.9
44.7
442.7
✓
12.7
32.4
86.9
71.7
544.3
82.5
69.8
540.4
63.4
47.7
450.9
✓
✓
12.9
25.5
86.5
71.3
543.1
81.9
69.1
538.7
62.2
47.1
449.1
Table 3: Ablation results (%) of the main components using VSE ∞ on ITR tasks. The best results are highlighted in bold , and the second best results are underlined .
Weight Precision
Gaussian Noise
Params. (M) ↓
Memory (G) ↓
Flickr30K
MSCOCO1K
MSCOCO5K
I-T ↑
T-I ↑
Rsum ↑
I-T ↑
T-I ↑
Rsum ↑
I-T ↑
T-I ↑
Rsum ↑
Full-Pre
12.4
24.4
84.8
69.1
537.4
80.6
67.5
532.9
61.1
45.9
445.3
Low-Pre
12.4
14.8
81.6
66.4
529.3
77.5
64.6
524.7
58.4
43.0
433.8
Mixed-Pre
12.4
15.4
82.1
66.7
531.4
77.8
65.0
526.9
58.8
43.5
437.2
Mixed-Pre
✓
12.5
18.4
83.7
68.1
534.8
78.9
66.3
530.4
59.9
44.7
442.7
Table 4: ( Top ) Ablation results (%) of GNP-IQ with various backbone weights precision (Full-, Mixed-, and Low-Precision), w/ or w/o Gaussian noise perturbation. ( Bottom ) Ablation results (%) of ISMoE w/ or w/o MoE structure and measuring correlation between networks. All experiments are conducted on ITR tasks with VSE ∞ . The best results are highlighted in bold , and the second best results are underlined .
State Key Laboratory of Virtual Reality Technology and Systems, Beihang University, China · School of Computer Science and Engineering, Beihang University, China · College of Information Technology, United Arab Emirates University, United Arab Emirates