Towards Easier-to-Tune Training Algorithms: New Results from AlgoPerf
Authors: Priya Kasimbeg, Ahmed Khaled, Aahlad Chandrabhatta, Yifan Wang, Andy Liu, Niccolò Ajroldi, David Tweedle, Xingyu, Yang, Isaac Patole, Frank Schneider, George E. Dahl
Organizations: Alice · Goodfire · University of Tübingen · Google
Evaluating deep learning optimizer is challenging because confounding factors such as hyperparameter tuning and optimizer-model co-design often obscure true algorithmic performance. We present results of the updated AlgoPerf V1 benchmark, in which we evaluate a new set of training algorithms on wall-clock time-to-target across nine workloads on fixed hardware. This report focuses on the results of the benchmark's self-tuning ruleset, which requires submissions to use a single configuration across all workloads. Out of the 13 submissions in PyTorch and JAX, Schedule-Free AdamW ranked first. In addition to the wall-clock scores, we also analyze the trade-offs between step efficiency and wall-clock execution, revealing that matrix-preconditioned and two-loop methods achieve good sample efficiency but require more aggressive computational optimizations to be competitive in runtime. Finally, our hyperparameter saliency and retention analyses show that the learning rate and momentum are highly sensitive across domains and algorithms, highlighting the need for methods that are more robust against hyperparameter tuning and can generalize well to new tasks.
Figures & tables
Validation
Base Runtime
Task
Dataset
Model
Loss
Metric
Target
Budget (s)
Clickthrough rate prediction
Criteo 1TB
DLRMsmall
CE
CE
0.123735
8915
MRI reconstruction
fastMRI
U-Net
L1
SSIM
0.723653
2745
Image
ImageNet
ResNet-50
CE
ER
0.22569
49,918
classification
ViT
CE
ER
0.22691
64,292
Speech
LibriSpeech
Conformer
CTC
WER
0.085884
43,680
Table 1: Summary of the nine AlgoPerf base workloads, validation targets, and base runtime budgets. The self-tuning runtime budgets are 1.5× these base values.
Algorithm
Brief Description
Citation
Submission Code
Schedule-Free AdamW v2 (PyTorch)
Couples momentum interpolation with dynamic iterate averaging; eliminates LR schedules and maintains batch norm statistics. This version makes use of the batch-norm fixes in AlgoPerf v1 and is as a result more faithful to the published version of Schedule-Free.
( Defazio et al., 2024 )
schedule_free_adamw_v2
AdEMAMix (AdamW equiv.) (PyTorch)
Blends fast and slow gradient EMAs to track short-term fluctuations while retaining long-term directional memory. This submission sets a long warmup for α and β3 making it effectively equivalent to AdamW.
( Pagliardini et al., 2025 )
ademamix
Schedule-Free AdamW (PyTorch)
Legacy Schedule-Free AdamW implementation submitted to the AlgoPerf competition. This version does not contain batch-norm fixes.
( Defazio et al., 2024 )
schedule_free_adamw
NAdamW (Baseline v0.5) (JAX)
Nesterov-accelerated adaptive gradient optimizer with decoupled weight decay. This version served as the prize qualification baseline for the AlgoPerf v0.5 competition.
( Dozat, 2016 ; Loshchilov and Hutter, 2019 )
nadamw_baselinev05
Schedule-Free AdamW v2 (JAX)
JAX implementation of Schedule-Free AdamW v2 with batch-normalization fix.
( Defazio et al., 2024 )
schedule_free_adamw_jax_v2
Muon (PyTorch)
Matrix-preconditioned optimizer applying quintic Newton-Schulz iterations on 2D or higher-dimensional non-embedding tensors with AdamW for 1D and embedding parameters.
( Jordan et al., 2024b )
muon_torch
Table 2: Summary of evaluated algorithms on the AlgoPerf self-tuning leaderboard.
Figure 1: AlgoPerf self-tuning leaderboard and performance profiles. The leaderboard ranks the submissions according to their AlgoPerf scores, which correspond to the areas under the curves of the performance profiles.
Figure 2: Wall-clock vs. step-based benchmark score per submission.
Figure 3: AlgoPerf score (left) and leaderboard rank (right) as targets are relaxed.
Figure 4: Workload–Hyperparameter Importance Heatmaps Across Optimizers. Normalized 1D Wasserstein importance indices ( W1/Span , Equation 1 ) across the AlgoPerf benchmark suite, evaluated at the top 10% best-performing trial threshold ( k=0.10 ). Higher values (darker red) denote hyperparameters that have to collapse into a narrow band to achieve top-tier performance, while lower values reflect broad robustness across the search space. Each subplot isolates the active hyperparameters specific to that optimizer.
Figure 5: Spans of learning rate across the top 5% configurations. Disjoint regions indicate fundamental tension for universal tuning. Note that for Muon, the LR indicates the learning rate applied to the paired optimizer and serves as a basis for the Muon LR multiplier.
Figure 6: Distribution of nine-workload mean time-based speedup scores ( Sˉ ) across hyperparameter sweeps for DiLoCo, NAdamW, Muon, and AdEMAMix ( N=100 per optimizer) under a 2× extrapolation horizon on the running-best validation trajectory. Vertical dashed red lines indicate medians; solid black lines mark the single golden configuration.
Tuning Metric
DiLoCo ( D=4 )
NAdamW ( D=3 )
Muon ( D=5 )
AdEMAMix ( D=7 )
Golden config score ( Sˉ(c∗) )
0.786
0.989
0.927
0.583
Oracle score ( Sˉ∗ )
1.279
1.509
1.973
1.403
Retention Rate ( R )
61.4%
65.5%
47.0%
41.5%
Median Speedup ( p50 )
0.427
0.000
0.063
0.000
Failure Rate ( P(Sˉ≤0.20) )
1.0%
70.0%
71.0%
85.0%
Table 3: Hyperparameter sensitivity metrics across N=100 configurations under extrapolated time-to-target scoring ( Sw(c)=Tmax,w/t^target , capped at t^target≤2Tmax,w ). Failure rate denotes Sˉ(c)≤0.20 .
Figure 7: Retention gap and tuning budget progression across optimizers under a 2× extrapolation horizon on the running-best validation trajectory. Left: Golden config score ( Sˉ(c∗) , single configuration across all 9 workloads) versus Oracle score ( Sˉ∗ , per-workload tuning) with retention percentage R=Sˉ(c∗)/Sˉ∗ . Right: Expected best speedup Sˉ as a function of tuning budget k∈[1,100] under universal search (dashed) versus per-workload search (solid); see below.
Figure 8: Training dynamics of Schedule-Free AdamW on the ImageNet ResNet workload. Calibrating Batch Normalization running statistics at xt rather than yt in Schedule-Free AdamW v2 (PyTorch) resolves the severe covariate shift that stalled validation progress in earlier iterations.
Framework
Implementation
HPs
Score
Δ
JAX
vanilla
JAX
0.2845
—
PyTorch
vanilla
JAX
0.2969
+0.012
PyTorch
sharded
JAX
0.3137
+0.017
PyTorch
sharded
Torch
0.4231
+0.109
PyTorch
vanilla
Torch
0.3827
−0.040
Table 4: Hyperparameter ablations on Muon submissions. In this table we compare the hypothetical scores for Muon (JAX) and Muon (PyTorch) submissions ablations in the overall submission pool. For the Muon (PyTorch) submissions we evaluate both the vanilla and sharded version on a combination of the hyperparameters found for the vanilla (JAX) implementation and the sharded (Torch) implementations. Each row changes one factor (bold) relative to the row above. Rows one and four are the leaderboard entries Muon (JAX) and Muon (PyTorch) ; the final row steps back down to the vanilla implementation.
Figure 9: Empirical speedup across workloads for Muon implementations, contrasting the communication-sharded Muon (PyTorch) against the replicated baseline.
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
Submission
Criteo 1TB
fastMRI
FineWeb-Edu 10B
ResNet
ViT
Conformer
DeepSpeech
OGBG
WMT
Schedule-Free AdamW v2 (PyTorch)
0.56
0.27
—
—
—
0.85
0.76
0.37
0.43
AdEMAMix (AdamW equiv.) (PyTorch)
0.59
0.37
0.38
—
—
0.75
—
0.37
0.72
Schedule-Free AdamW (PyTorch)
0.77
0.29
—
—
—
—
0.73
0.21
0.83
NAdamW (Baseline v0.5) (JAX)
0.61
0.39
0.43
—
—
—
—
0.24
0.62
Schedule-Free AdamW v2 (JAX)
0.61
0.45
0.32
—
0.88
—
—
0.32
—
Muon (PyTorch)
0.53
—
0.32
—
—
—
—
0.11
0.59
Appendix
Table 5: Time to target as a fraction of each workload’s self-tuning-ruleset time budget ( 1.5× the external-tuning maximum allowed runtime). — = target not reached.
Submission
Criteo 1TB
fastMRI
FineWeb-Edu 10B
ResNet
ViT
Conformer
DeepSpeech
OGBG
WMT
JAX submissions
Schedule-Free AdamW (JAX)
1.67
1.25
0.51
1.04
1.33
1.00
0.47
1.05
1.05
Schedule-Free AdamW v2 (JAX)
1.00
0.96
0.52
1.17
1.10
1.06
1.04
1.03
1.05
Muon (JAX)
1.96
0.97
1.16
1.47
1.24
1.00
1.00
1.01
1.39
NAdamW (JAX)
1.01
0.73
1.00
0.99
1.00
0.97
0.91
1.01
1.01
NAdamW (Baseline v0.5) (JAX)
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Appendix
Table 6: Step execution times, normalized to NAdamW (Baseline v0.5) (JAX) . Each value is the ratio of a submission’s average time per step to the reference’s on that workload, excluding the first evaluation interval to remove compilation time; submissions run at their own batch sizes.
Wall-clock
Steps
Submission
Score
Rank
Score
Rank
Δ
Schedule-Free AdamW v2 (PyTorch)
0.5679
1
0.5253
1
–
AdEMAMix (AdamW equiv.) (PyTorch)
0.5191
2
0.5146
2
–
Schedule-Free AdamW (PyTorch)
0.4669
3
0.4461
3
–
NAdamW (Baseline v0.5) (JAX)
0.4506
4
0.4422
4
–
Schedule-Free AdamW v2 (JAX)
0.4405
5
0.3945
6
↓ 1
Appendix
Table 7: Wall-clock vs. step-based benchmark scores. Both use the same performance-profile scoring; only the notion of training time differs (seconds vs. optimizer steps to target). Δ is the rank change when moving from wall-clock to step-based scoring.
Figure 10: AlgoPerf self-tuning leaderboard and performance profiles (steps to target).
Submission
Criteo 1TB
fastMRI
FineWeb-Edu 10B
ResNet
ViT
Conformer
DeepSpeech
OGBG
WMT
Schedule-Free AdamW v2 (PyTorch)
7,951
12,431
—
—
—
83,184
78,669
28,449
73,222
AdEMAMix (AdamW equiv.) (PyTorch)
8,371
10,206
44,503
—
—
67,706
—
27,247
112,742
Schedule-Free AdamW (PyTorch)
10,346
10,599
—
—
—
—
90,588
15,853
133,517
NAdamW (Baseline v0.5) (JAX)
9,145
6,648
47,039
—
—
—
—
20,879
118,600
Muon (PyTorch)
7,716
—
39,220
—
—
—
—
7,711
97,224
Schedule-Free AdamW v2 (JAX)
9,005
8,750
68,640
—
164,206
—
—
27,457
—
Appendix
Table 8: Median number of optimizer steps to reach the validation target. — = target not reached. Submissions choose their own batch sizes, so step counts compare optimizer updates, not examples seen.
Standard
10% relaxed
Submission
Score
Rank
Score
Rank
Δ
Schedule-Free AdamW v2 (JAX)
0.4405
5
0.6852
1
↑ 4
AdEMAMix (PyTorch)
0.2464
12
0.6246
2
↑ 10
Schedule-Free AdamW v2 (PyTorch)
0.5679
1
0.6072
3
↓ 2
Muon (PyTorch)
0.4231
6
0.5993
4
↑ 2
Schedule-Free AdamW (PyTorch)
0.4669
3
0.5786
5
↓ 2
Appendix
Table 9: Standard vs. 10% relaxed-target AlgoPerf self-tuning leaderboard. Δ is the rank change after relaxing targets.
Figure 11: AlgoPerf self-tuning leaderboard and performance profiles with 10% relaxed targets.
Submission
Criteo 1TB
fastMRI
FineWeb-Edu 10B
ResNet
ViT
Conformer
DeepSpeech
OGBG
WMT
Schedule-Free AdamW v2 (JAX)
0.03
0.07
0.21
0.11
0.27
—
—
0.13
0.08
AdEMAMix (PyTorch)
0.03
0.09
0.16
—
—
0.67
0.44
0.16
0.14
Schedule-Free AdamW v2 (PyTorch)
0.03
0.06
0.59
—
—
0.61
0.42
0.16
0.06
Muon (PyTorch)
0.03
0.08
0.22
—
—
0.72
—
0.08
0.08
Schedule-Free AdamW (PyTorch)
0.03
0.08
—
—
—
0.72
0.42
0.13
0.08
Schedule-Free AdamW (JAX)
0.03
0.09
0.16
—
0.27
—
—
0.16
0.08
Appendix
Table 10: Time to target with targets relaxed 10%, as a fraction of each workload’s self-tuning-ruleset time budget ( 1.5× the external-tuning maximum allowed runtime). Bold values mark targets reached only after relaxation; — = target not reached.
Figure 12: Validation metric against wall-clock time for Muon (PyTorch) , Muon (JAX) , and Lion (PyTorch) on the nine base workloads. Lines show the mean over three studies and shaded bands show ±1 standard deviation. The dotted line marks the validation target. Solid lines are PyTorch and dashed lines are JAX implementations. Minimized metrics (loss, WER, perplexity) are on a logarithmic axis. Each curve ends when its longest study stops, either at the target or at the time budget. Muon (JAX) uses different fixed hyperparameters from Muon (PyTorch) . The two differ most on ImageNet ResNet-50 and ImageNet ViT, where Muon (JAX) reaches higher accuracy, and on OGBG GNN and WMT Transformer, where it levels off below the target.
Figure 13: Validation metric against wall-clock time for NAdamW (JAX) , NAdamW (Baseline v0.5) (JAX) , Cautious NAdamW (JAX) , and Single-worker DiLoCo (JAX) on the nine base workloads. All four are JAX implementations. Lines show the mean over three studies and shaded bands show ±1 standard deviation. Minimized metrics (loss, WER, perplexity) are on a logarithmic axis. Single-worker DiLoCo (JAX) trails the NAdamW variants on ImageNet ViT, LibriSpeech Conformer, and OGBG GNN. Cautious NAdamW (JAX) shows a loss spike on Criteo 1TB DLRMsmall and regresses after about four hours on LibriSpeech DeepSpeech.
Figure 14: Validation metric against wall-clock time for the four Schedule-Free AdamW submissions ( Schedule-Free AdamW (PyTorch) , Schedule-Free AdamW v2 (PyTorch) , Schedule-Free AdamW (JAX) , Schedule-Free AdamW v2 (JAX) ) and the two AdEMAMix submissions ( AdEMAMix (AdamW equiv.) (PyTorch) , AdEMAMix (PyTorch) ) on the nine base workloads. Lines show the mean over three studies and shaded bands show ±1 standard deviation. The dotted line marks the validation target. Solid lines are PyTorch and dashed lines are JAX implementations. Minimized metrics (loss, WER, perplexity) are on a logarithmic axis. On ImageNet ResNet-50, the first versions of Schedule-Free AdamW ( Schedule-Free AdamW (PyTorch) , Schedule-Free AdamW (JAX) ) oscillate while both v2 submissions train stably. On ImageNet ViT, the JAX implementations nearly reach the target while the PyTorch submissions level off near 0.65 accuracy.
Optimizer
Tuned Hyperparameter
Sampling Range / Values
Distribution
Fixed Parameters & Architectural Notes
NAdamW ( D=7 )
Learning rate ( η )
[10−5,5×10−3]
Log-uniform
Cosine decay schedule ( cosine_warmup )
Momentum 1−β1
[10−3,0.5]
Log-uniform
Fixed ϵ=10−8 , bias correction ( debias = True )
Second moment 1−β2
[10−3,0.5]
Log-uniform
Tied dropout rates ( tie_dropouts = True , when supported)
Weight decay ( λ )
[10−2,0.5]
Log-uniform
l2_decay_factor = None
LR warmup fraction ( Twarmup )
{0.02,0.05,0.10}
Discrete uniform
∗ Tuned only on workloads supporting the regularizer
Label smoothing ∗
{0.0,0.2}
Discrete uniform
Appendix
Table 11: Hyperparameter search space specifications for the N=100 quasi-random Halton sweeps evaluated across all nine AlgoPerf workloads.
Figure 15: Comparison of sampled search space vs. optimal hyperparameter distributions. Empirical density (KDE) of hyperparameter values across workloads, comparing all sampled configurations (dashed line, light fill) to the top-10% best-performing trials (solid line, dark fill). Regions where the top-10% density is significantly more concentrated or peaked relative to the sample space indicate favorable hyperparameter settings for that workload.
Figure 16: Comparison of sampled search space vs. optimal hyperparameter distributions. Empirical density (KDE) of hyperparameter values across workloads, comparing all sampled configurations (dashed line, light fill) to the top-10% best-performing trials (solid line, dark fill). Regions where the top-10% density is significantly more concentrated or peaked relative to the sample space indicate favorable hyperparameter settings for that workload.
Figure 17: Comparison of sampled search space vs. optimal hyperparameter distributions. Empirical density (KDE) of hyperparameter values across workloads, comparing all sampled configurations (dashed line, light fill) to the top-10% best-performing trials (solid line, dark fill). Regions where the top-10% density is significantly more concentrated or peaked relative to the sample space indicate favorable hyperparameter settings for that workload.
Figure 18: Comparison of sampled search space vs. optimal hyperparameter distributions. Empirical density (KDE) of hyperparameter values across workloads, comparing all sampled configurations (dashed line, light fill) to the top-10% best-performing trials (solid line, dark fill). Regions where the top-10% density is significantly more concentrated or peaked relative to the sample space indicate favorable hyperparameter settings for that workload.
Figure 19: JAX vs. PyTorch median time per training step. Batch sizes and hyperparameters are held constant across frameworks.