Jet tagging is one of the most important applications of machine learning at the Large Hadron Collider. Recent models build in more physics knowledge or rely on large-scale pretraining, but the experiments place strict limits on their inference cost. Knowledge distillation can transfer their performance to small students that are cheap to run. We ask which properties of a teacher help the student, how small a student can get and how close it can come to the state of the art. On a jet tagging benchmark, we distil six teachers that differ in architecture, symmetry and pretraining, including two foundation models, into five small students. Every teacher improves every student, and the gain depends mainly on the strength of the teacher. We then shrink our two strongest distilled students, Transformer and L-GATr-slim, in width and in depth. With 20 thousand parameters, a distilled L-GATr-slim outperforms every published jet tagger trained from scratch at a fraction of the inference cost of every teacher. Even with two thousand parameters, it matches ParT, a model with a thousand times as many parameters. We also study what the students learn from their teachers. Our benchmark of inference cost shows that students of the same size can differ by almost an order of magnitude in speed. We release the code and the weights of all trained models.
Figures & tables
Teacher
Params
AUC
1/ϵB ( ϵS=0.5 )
1/ϵB ( ϵS=0.3 )
ParT
2.1M
0.98571 ± 0.00011
394 ± 14
1,586 ± 19
MIParT
0.7M
0.98632 ± 0.00005
467 ± 5
1,871 ± 69
L-GATr ∗
1.1M
0.98680 ± 0.00005
528 ± 14
2,189 ± 176
L-GATr-slim ∗
2.0M
0.98711 ± 0.00008
541 ± 5
2,321 ± 46
OmniLearned-S †
2.7M
0.98746 ± 0.00001
546 ± 11
2,403 ± 100
ParT-f.t. †
2.1M
0.98769 ± 0.00005
644 ± 16
2,556 ± 0.2
Table 1: Teacher performance on the top-tagging test set: AUC and background rejection 1/ϵB at two signal efficiencies ϵS . We mark Lorentz-equivariant models with an asterisk and pretrained models with a dagger, and give means and standard deviations over three runs.
Student
Params
AUC
1/ϵB ( ϵS=0.5 )
1/ϵB ( ϵS=0.3 )
Transformer
188k
0.98512 ± 0.00013
393 ± 5
1,612 ± 121
LorentzNet ∗
203k
0.98556 ± 0.00010
413 ± 16
1,714 ± 83
ParT
205k
0.98565 ± 0.00004
384 ± 7
1,603 ± 76
MIParT
200k
0.98580 ± 0.00019
410 ± 5
1,767 ± 83
L-GATr-slim ∗
202k
0.98622 ± 0.00016
425 ± 20
1,704 ± 80
Table 2: Students trained without a teacher: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 , with means and standard deviations over three runs.
Figure 1: Background rejection 1/ϵB at ϵS=0.5 (top) and ϵS=0.3 (bottom) of every student, trained without a teacher and distilled from each teacher. Black lines and grey bands show the teachers. We show means and standard deviations over three runs.
Student
Teacher
Transformer
LorentzNet ∗
ParT
MIParT
L-GATr-slim ∗
No teacher
0.98512 ± 0.00013
0.98556 ± 0.00010
0.98565 ± 0.00004
0.98580 ± 0.00019
0.98622 ± 0.00016
ParT
0.98617 ± 0.00010
0.98630 ± 0.00010
0.98607 ± 0.00001
0.98624 ± 0.00005
0.98643 ± 0.00005
MIParT
0.98646 ± 0.00007
0.98655 ± 0.00010
0.98622 ± 0.00008
0.98631 ± 0.00002
0.98660 ± 0.00001
L-GATr ∗
0.98680 ± 0.00011
0.98671 ± 0.00018
0.98659 ± 0.00007
0.98675 ± 0.00007
0.98693 ± 0.00001
L-GATr-slim ∗
0.98691 ± 0.00006
0.98685 ± 0.00014
0.98671 ± 0.00011
0.98690 ± 0.00011
0.98712 ± 0.00007
Table 3: AUC of every student (columns), trained without a teacher and distilled from each teacher (rows), with means and standard deviations over three runs.
Figure 2: Gain of every student from distillation against the AUC of its teacher, in AUC (left) and relative background rejection 1/ϵB at ϵS=0.5 (right). Black ticks show the mean over the five students. All values are means over three runs.
Figure 3: Width study: background rejection 1/ϵB at ϵS=0.3 of ten-block students of decreasing width, trained without a teacher (dotted, hollow) and distilled from three teachers (solid, filled). Darker lines mark stronger teachers, and grey dashed lines show the teachers. Error bars show standard deviations over three runs.
No teacher
ParT-f.t. †
1/ϵB
1/ϵB
Student
Params
AUC
ϵS=0.5
ϵS=0.3
AUC
ϵS=0.5
ϵS=0.3
Transformer
1.2k
0.97422 ± 0.00052
115 ± 4
398 ± 27
0.97401 ± 0.00049
112 ± 5
377 ± 11
16k
0.98388 ± 0.00012
318 ± 14
1,246 ± 57
0.98624 ± 0.00019
488 ± 8
1,975 ± 67
84k
0.98495 ± 0.00012
373 ± 8
1,431 ± 46
0.98688 ± 0.00009
557 ± 18
2,347 ± 57
L-GATr-slim ∗
1.8k
0.98491 ± 0.00018
358 ± 5
1,449 ± 86
0.98567 ± 0.00004
416 ± 22
1,872 ± 153
Table 4: Width study: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 of ten-block students of three widths, trained without a teacher and distilled from ParT-f.t., with means and standard deviations over three runs. Table 12 gives the other two teachers.
Figure 4: Depth study: background rejection 1/ϵB at ϵS=0.3 of students of fixed width with a varying number of blocks, trained without a teacher (dotted, hollow) and distilled from three teachers (solid, filled), one run each. Darker lines mark stronger teachers, and grey dashed lines show the teachers.
Figure 5: What Transformer and L-GATr-slim learn from their teacher, distilled (solid, filled) and trained without a teacher (dotted, hollow). (a) KL divergence from ParT-f.t. to the student against the number of student parameters in the width study. (b) Percentage of the background jets each teacher accepts at ϵS=0.5 that the student also accepts. (c, d) Probability the student assigns to the true class minus that of ParT-f.t., for signal (c) and background (d) jets, in ten groups of equal size ordered by the probability ParT-f.t. assigns to the true class. All values are means over three runs.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Teachers
ParT
2.1M
0.98571
394 ± 14
1,586 ± 19
197
18,198
1,099
7.9
MIParT
0.7M
0.98632
467 ± 5
1,871 ± 69
76.0
7,225
5,132
8.9
L-GATr ∗
1.1M
0.98680
528 ± 14
2,189 ± 176
1,868
4,263
707
50.5
L-GATr-slim ∗
2.0M
0.98711
541 ± 5
2,321 ± 46
309
16,546
339
8.1
Table 5: Performance and inference cost on real test jets in the fastest 32-bit setting: operations per jet in millions (median over 300 jets, one multiply-accumulate counted as two), GPU throughput and peak memory at a batch of 512 jets and CPU latency for one jet on one core. Teachers are shown with their own performance and students after distillation from ParT-f.t., with standard deviations of the background rejection over three runs. Deep Sets + GNN [ 5 ] is distilled from OmniLearned-L, and its performance is as published. Appendix G gives the same table without a teacher and for every other teacher.
Figure 6: Background rejection 1/ϵB at ϵS=0.5 (left) and ϵS=0.3 (right) against (a) GPU time per jet and (b) GPU peak memory at a batch of 512 jets, (c) CPU latency for one jet and (d) operations per jet, in the fastest 32-bit setting. Students distilled from ParT-f.t. are filled and teachers hollow, and (d) gives the sizes of the Transformer and L-GATr-slim students. Error bars show standard deviations over three runs.
Appendix figures & tables28 assets
Supplementary material from the paper’s appendix.
Appendix
Model
Width
Heads
Blocks
Read-out
Params
Teachers
ParT
128
8
8 + 2
class token
2,141,005
MIParT
64
8
5 + 5 + 2
class token
656,949
L-GATr ∗
16 mv, 32 s
8
12
global token
1,077,474
L-GATr-slim ∗
32 v, 96 s
8
12
global token
2,030,817
OmniLearned-S †
128
8
8 + 2
4 class tokens
2,708,149
Appendix
Table 6: Configuration of every model. Width counts hidden channels, as multivector (mv), vector (v) and scalar (s) channels for the L-GATr family; blocks counts the blocks of each model, with a sum for blocks of different kinds.
Model
Optimizer
Learning rate
Weight decay
Batch
Steps
Schedule
Transformer
AdamW
10−3
0.1
256
200,000
cosine
LorentzNet ∗
AdamW
10−3
10−2
128
336,000
cosine
ParT
Ranger
10−3
10−2
512
48,000
flat, then decay
MIParT
Ranger
10−3
10−2
256
72,000
flat, then decay
L-GATr-slim ∗
Lion
3×10−5
2
128
200,000
cosine
Transformer 84k
AdamW
10−3
0.1
256
200,000
cosine
Appendix
Table 7: Training recipes. Steps are optimizer updates.
This work
Published
1/ϵB
1/ϵB
Model
Params
AUC
ϵS=0.5
ϵS=0.3
Params
AUC
ϵS=0.5
ϵS=0.3
ParT
2.1M
0.98571 ± 0.00011
394 ± 14
1,586 ± 19
2.1M
0.9858
413 ± 16
1,602 ± 81
MIParT
0.7M
0.98632 ± 0.00005
467 ± 5
1,871 ± 69
0.7M
0.9868
505 ± 8
2,010 ± 97
L-GATr ∗
1.1M
0.98680 ± 0.00005
528 ± 14
2,189 ± 176
1.1M
0.9870 ± 0.0001
540 ± 20
2,240 ± 70
L-GATr-slim ∗
2.0M
0.98711 ± 0.00008
541 ± 5
2,321 ± 46
2.0M
0.9869 ± 0.0001
546 ± 7
2,264 ± 93
Appendix
Table 8: Performance of the teachers and of LorentzNet trained without a teacher, with means and standard deviations over three runs, and the published performance of the same models [ 35 , 42 , 37 , 33 , 6 , 21 ] .
Single run
Ensemble of three runs
1/ϵB
1/ϵB
Teacher
AUC
ϵS=0.5
ϵS=0.3
AUC
ϵS=0.5
ϵS=0.3
ParT
0.98571 ± 0.00011
394 ± 14
1,586 ± 19
0.98630
448
1,960
MIParT
0.98632 ± 0.00005
467 ± 5
1,871 ± 69
0.98663
499
1,972
L-GATr ∗
0.98680 ± 0.00005
528 ± 14
2,189 ± 176
0.98719
554
2,462
L-GATr-slim ∗
0.98711 ± 0.00008
541 ± 5
2,321 ± 46
0.98748
589
2,490
Appendix
Table 9: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 of every teacher as a single run, with the mean and standard deviation over three runs, and as the ensemble of its three runs, which averages their logits.
Student
Teacher
Transformer
LorentzNet ∗
ParT
MIParT
L-GATr-slim ∗
AUC
L-GATr-slim ∗
0.98691 ± 0.00006
0.98685 ± 0.00014
0.98671 ± 0.00011
0.98690 ± 0.00011
0.98712 ± 0.00007
L-GATr-slim ∗ ens.
0.98701 ± 0.00003
0.98711 ± 0.00009
0.98678 ± 0.00010
0.98698 ± 0.00010
0.98719 ± 0.00003
OmniLearned-S †
0.98705 ± 0.00007
0.98713 ± 0.00018
0.98677 ± 0.00010
0.98705 ± 0.00010
0.98727 ± 0.00002
1/ϵB at ϵS=0.5
Appendix
Table 10: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 of every student of Section 4 distilled from L-GATr-slim, from the ensemble of its three runs (L-GATr-slim ens.) and from OmniLearned-S, with means and standard deviations over three runs.
Student
Teacher
Transformer
LorentzNet ∗
ParT
MIParT
L-GATr-slim ∗
1/ϵB at ϵS=0.5
No teacher
393 ± 5
413 ± 16
384 ± 7
410 ± 5
425 ± 20
ParT
441 ± 20
446 ± 25
423 ± 12
441 ± 12
458 ± 12
MIParT
482 ± 9
488 ± 2
448 ± 10
474 ± 11
487 ± 9
L-GATr ∗
537 ± 14
527 ± 9
512 ± 8
523 ± 9
533 ± 24
Appendix
Table 11: Background rejection 1/ϵB at ϵS=0.5 (top) and ϵS=0.3 (bottom) of every student (columns), trained without a teacher and distilled from each teacher (rows). Means and standard deviations over three runs.
Figure 7: Width study: background rejection 1/ϵB at ϵS=0.5 of ten-block students of decreasing width, trained without a teacher (dotted, hollow) and distilled from three teachers (solid, filled, darker for a stronger teacher). Error bars show the standard deviation over three runs, and grey dashed lines show the rejection of the teachers.
Figure 8: Depth study: background rejection 1/ϵB at ϵS=0.5 of students of fixed width with a varying number of blocks, trained without a teacher (dotted, hollow) and distilled from three teachers (solid, filled, darker for a stronger teacher), one run each. Grey dashed lines show the rejection of the teachers.
L-GATr ∗
OmniLearned-S †
1/ϵB
1/ϵB
Student
Params
AUC
ϵS=0.5
ϵS=0.3
AUC
ϵS=0.5
ϵS=0.3
Transformer
1.2k
0.97391 ± 0.00031
113 ± 5
391 ± 26
0.97360 ± 0.00038
111 ± 3
377 ± 17
16k
0.98590 ± 0.00009
457 ± 9
1,876 ± 142
0.98615 ± 0.00021
468 ± 20
1,976 ± 120
84k
0.98658 ± 0.00011
503 ± 19
2,230 ± 133
0.98669 ± 0.00006
530 ± 6
2,152 ± 183
L-GATr-slim ∗
1.8k
0.98560 ± 0.00012
403 ± 2
1,773 ± 67
0.98543 ± 0.00046
404 ± 16
1,731 ± 167
Appendix
Table 12: Width study: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 of ten-block students of three widths, distilled from L-GATr and OmniLearned-S. Means and standard deviations over three runs.
No teacher
ParT-f.t. †
1/ϵB
1/ϵB
Student
Blocks
Params
AUC
ϵS=0.5
ϵS=0.3
AUC
ϵS=0.5
ϵS=0.3
Transformer
0
433
0.86367
10
16
0.86364
10
16
1
19k
0.98143
222
869
0.98275
257
1,128
2
38k
0.98360
300
1,224
0.98577
435
1,771
3
57k
0.98459
346
1,355
0.98648
492
2,103
Appendix
Table 13: Depth study: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 of students of fixed width with a varying number of blocks, trained without a teacher and distilled from ParT-f.t., one run each.
L-GATr ∗
OmniLearned-S †
1/ϵB
1/ϵB
Student
Blocks
Params
AUC
ϵS=0.5
ϵS=0.3
AUC
ϵS=0.5
ϵS=0.3
Transformer
0
433
0.86357
10
16
0.86364
10
16
1
19k
0.98295
273
1,091
0.98261
257
1,020
2
38k
0.98549
408
1,836
0.98557
425
1,711
3
57k
0.98641
502
2,148
0.98647
506
2,040
Appendix
Table 14: Depth study: AUC and background rejection 1/ϵB at ϵS=0.5 and 0.3 of students of fixed width with a varying number of blocks, distilled from L-GATr and OmniLearned-S, one run each.
Figure 9: KL divergence from the teacher’s predicted probabilities to the student’s against the number of student parameters, for the three teachers of the scaling studies, in the width study (top, means over three runs) and the depth study (bottom, one run, three at the depth of Section 4 ). Transformer and L-GATr-slim are shown distilled (solid, filled) and trained without a teacher (dotted, hollow).
Figure 10: Of the background jets each teacher accepts at ϵS=0.5 (left) and ϵS=0.3 (right), the percentage every student of Section 4 also accepts at the same signal efficiency, distilled (filled) and trained without a teacher (hollow). Means over three runs.
Figure 11: For each teacher, the percentage of the background jets it accepts and another teacher rejects that the student also accepts at ϵS=0.5 (left) and ϵS=0.3 (right), when distilled from this teacher, distilled from the other teacher or trained without a teacher. Means over the five other teachers, the five students of Section 4 and three runs.
Figure 12: Background jets Transformer and L-GATr-slim accept at ϵS=0.5 among those each teacher rejects (left) and accepts (right), with distillation (solid, filled) and without (dotted, hollow). Means over three runs.
Transformer
LorentzNet ∗
ParT
MIParT
L-GATr-slim ∗
Teacher
without
with
without
with
without
with
without
with
without
with
Background jets the teacher rejects
ParT
185
87
178
76
179
105
163
87
145
71
MIParT
201
74
183
69
186
91
150
60
156
61
L-GATr ∗
248
77
222
85
243
105
217
87
191
73
L-GATr-slim ∗
253
88
224
91
255
111
229
95
200
74
Appendix
Table 15: Background jets every student of Section 4 accepts at ϵS=0.5 , without and with distillation, among the jets each teacher rejects (top) and accepts (bottom). Means over three runs.
Figure 13: Probability every student of Section 4 assigns to the true class minus that assigned by ParT-f.t., for signal (left) and background (right) jets in ten groups of equal size and increasing ParT-f.t. confidence, distilled (solid, filled) and trained without a teacher (dotted, hollow). Means over three runs.
Figure 14: Probability every student of Section 4 assigns to the true class minus that assigned by OmniLearned-S, for signal (left) and background (right) jets in ten groups of equal size and increasing OmniLearned-S confidence, distilled (solid, filled) and trained without a teacher (dotted, hollow). Means over three runs.
Figure 15: Probability every student of Section 4 assigns to the true class minus that assigned by L-GATr, for signal (left) and background (right) jets in ten groups of equal size and increasing L-GATr confidence, distilled (solid, filled) and trained without a teacher (dotted, hollow). Means over three runs.
Figure 16: Operations per jet, GPU throughput and peak memory at a batch of 512 jets and CPU latency for one jet on one core against the number of parameters, for every model of Table 5 , on real test jets in the fastest 32-bit setting.
Fastest setting
Model
Particle lists
Attention
GPU
CPU
ParT
padded
built-in
padded, compiled, built-in
padded, compiled, built-in
MIParT
padded
built-in
padded, compiled, built-in
padded, compiled, built-in
L-GATr ∗
packed, padded
xFormers, Flex
packed, compiled, xFormers
padded, compiled, xFormers
L-GATr-slim ∗
packed, padded
xFormers, Flex
packed, compiled, xFormers
packed, compiled, xFormers
OmniLearned-S †
padded
built-in
padded, compiled, built-in
padded, compiled, built-in
Appendix
Table 16: Execution settings timed for every model: particle lists and attention kernels (Flex: FlexAttention), each eager and compiled, and the fastest setting on each device, which Tables 5 and 17 report.
GPU
CPU
Model
Params
jets/s
MB
ms/jet
Teachers
ParT
2.1M
38,503
388
7.3
MIParT
0.7M
28,320
1,007
8.5
L-GATr ∗
1.1M
5,641
785
47.6
L-GATr-slim ∗
2.0M
17,485
351
7.6
Appendix
Table 17: Inference cost on jets with exactly 50 particles and random momenta: GPU throughput and peak memory at a batch of 512 jets and CPU latency for one jet on one core, each in the fastest 32-bit setting.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Students
Transformer
188k
0.98512
393 ± 5
1,612 ± 121
21.6
70,175
87
2.7
LorentzNet ∗
203k
0.98556
413 ± 16
1,714 ± 83
537
7,601
1,722
11.0
ParT
205k
0.98565
384 ± 7
1,603 ± 76
21.9
26,228
2,166
2.3
MIParT
200k
0.98580
410 ± 5
1,767 ± 83
20.4
12,181
1,709
7.8
Appendix
Table 18: Performance and inference cost of the students trained without a teacher.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Teacher
ParT
2.1M
0.98571
394 ± 14
1,586 ± 19
197
18,198
1,099
7.9
Students
Transformer
188k
0.98617
441 ± 20
1,826 ± 143
21.6
70,175
87
2.7
LorentzNet ∗
203k
0.98630
446 ± 25
1,897 ± 96
537
7,601
1,722
11.0
Appendix
Table 19: Performance and inference cost of the students distilled from ParT and of ParT itself.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Teacher
MIParT
0.7M
0.98632
467 ± 5
1,871 ± 69
76.0
7,225
5,132
8.9
Students
Transformer
188k
0.98646
482 ± 9
1,834 ± 95
21.6
70,175
87
2.7
LorentzNet ∗
203k
0.98655
488 ± 2
1,758 ± 71
537
7,601
1,722
11.0
Appendix
Table 20: Performance and inference cost of the students distilled from MIParT and of MIParT itself.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Teacher
L-GATr ∗
1.1M
0.98680
528 ± 14
2,189 ± 176
1,868
4,263
707
50.5
Students
Transformer
188k
0.98680
537 ± 14
2,294 ± 166
21.6
70,175
87
2.7
LorentzNet ∗
203k
0.98671
527 ± 9
2,260 ± 37
537
7,601
1,722
11.0
Appendix
Table 21: Performance and inference cost of the students distilled from L-GATr and of L-GATr itself.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Teacher
L-GATr-slim ∗
2.0M
0.98711
541 ± 5
2,321 ± 46
309
16,546
339
8.1
Students
Transformer
188k
0.98691
546 ± 10
2,374 ± 103
21.6
70,175
87
2.7
LorentzNet ∗
203k
0.98685
539 ± 6
2,261 ± 38
537
7,601
1,722
11.0
Appendix
Table 22: Performance and inference cost of the students distilled from L-GATr-slim and of L-GATr-slim itself.
1/ϵB
GPU
CPU
Model
Params
AUC
ϵS=0.5
ϵS=0.3
MFLOP
jets/s
MB
ms/jet
Teacher
OmniLearned-S †
2.7M
0.98746
546 ± 11
2,403 ± 100
427
3,736
13,221
17.0
Students
Transformer
188k
0.98705
565 ± 6
2,325 ± 121
21.6
70,175
87
2.7
LorentzNet ∗
203k
0.98713
536 ± 12
2,483 ± 120
537
7,601
1,722
11.0
Appendix
Table 23: Performance and inference cost of the students distilled from OmniLearned-S and of OmniLearned-S itself.
Jet tagging uses particle-collision data to classify jets by their underlying particles or processes, supporting precision measurements and searches for new physics.
Tabular foundation models (TFMs) achieve strong predictive performance through in-context learning, yet repeatedly conditioning on labeled data makes inference expensive. Knowledge distillation can reduce this cost by transferring their predictive ability to lightweight, dataset-specific students. However, the dependence of TFM predictions on both a labeled context and a query introduces two design questions: how to construct teacher supervision and whether expanding query coverage improves distillation. We examine these questions across two TFMs and both neural and tree-based students, and derive an effective distillation recipe. The recipe uses the full labeled training set as teacher context and trains students solely on teacher predictions for observed and synthetic queries. On TabArena, the resulting students outperform their supervised trained tuned-and-ensembled counterparts by 57-98 Elo points. Applied unchanged to TALENT, the same recipe improves matched default students on 236-258 of 300 datasets and reduces median primary error by 4.0-6.4%. The distilled students also achieve median inference speedups of 3.0-21.6 times over their teachers, offering a practical trade-off between predictive performance and repeated inference cost. Code is available at https://github.com/nums-ai/TFM_Distillation .
Foundation models deliver strong perception but are often too computationally heavy to deploy, and adapting them typically requires costly annotations. We introduce a semi-supervised knowledge distillation (SSKD) framework that compresses pre-trained vision foundation models (VFMs) into compact experts using limited labeled and abundant unlabeled data, and instantiate it for instance segmentation where per-pixel labels are particularly expensive. The framework unfolds in three stages: (1) domain adaptation of the VFM(s) via self-training with contrastive calibration, (2) knowledge transfer through a unified multi-objective loss, and (3) student refinement to mitigate residual pseudo-label bias. Central to our approach is an instance-aware pixel-wise contrastive loss that fuses mask and class scores to extract informative negatives and enforce clear inter-instance margins. By maintaining this contrastive signal across both adaptation and distillation, we align teacher and student embeddings and more effectively leverage unlabeled images. On Cityscapes and ADE20K, our ≈11× smaller student improves over its zero-shot VFM teacher(s) by +11.9 and +8.6 AP, surpasses adapted teacher(s) by +3.4 and +1.5 AP, and outperforms state-of-the-art SSKD methods on benchmarks.
Small language models are often the only option for deployment under tight latency, cost, and on-premises constraints, but they are rarely trained from scratch: a compressed model is usually recovered through knowledge distillation (KD). This recovery step largely decides the final quality, yet it is expensive. We present a practitioner's study of how to make distillation training efficient, organised around two systems contributions. First, we show that offline KD (caching the teacher's top-K logits once and training the student against the cache) matches online distillation at near-identical training loss while removing the teacher from memory, running about 29% faster per iteration, and reaching up to 41% higher throughput on a single H200 GPU. Second, we introduce a fused, chunked KL loss that never materialises the full vocabulary-sized logit tensor, making peak memory linear in the sequence length. This removes the memory spike that otherwise caps context length and lets us train at four times the context (32{,}768 tokens) on a single GPU. A separate output-head-only toy benchmark isolates the loss kernel and confirms its memory and iteration-rate scaling from 4K to 256K tokens. Together these make large-scale healing and hundreds of ablations affordable. We also report supporting ablations on loss design and sequence packing. We release our chunked-loss implementation: https://github.com/CompactifAI/Full-Chunked-KL-Loss.
Bakbergen Ryskulov, Iker García-Ferrero, David Montero +5