REVIEW 3 major objections 1 minor 1 cited by
Unstructured pruning can improve test-time scaling performance in reasoning LLMs, sometimes outperforming the original full models.
Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →
2026-07-01 09:14 UTC pith:MFCSPPSD
load-bearing objection Unstructured pruning can match or beat dense models on TTS according to the experiments, but the gains appear tied to hand-tuned layer-wise sparsity allocations that the paper does not separate from the pruning effect. the 3 major comments →
Revisiting the Effectiveness of LLM Pruning for Test-Time Scaling
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The paper claims that unstructured pruning augments TTS performance compared to structured pruning, and at times can even outperform the unpruned full-weight LLMs on reasoning benchmarks. It further shows that different layer-wise sparsity allocation strategies affect these outcomes, challenging the conventional notion that pruning always reduces TTS performance.
What carries the argument
Unstructured pruning with layer-wise sparsity allocation strategies that selectively remove individual weights while keeping full layer structure intact.
Load-bearing premise
The unstructured pruning methods rely on carefully chosen layer-wise sparsity allocation strategies.
What would settle it
Reproducing the experiments on the same models and benchmarks and finding that unstructured-pruned versions underperform or match but do not exceed the full models on TTS metrics would falsify the central claim.
If this is right
- Unstructured pruning can produce more efficient reasoning models that retain or gain TTS effectiveness.
- Layer-wise sparsity allocation choices determine whether pruning helps or hurts TTS performance.
- Pruning at the weight level does not inherently degrade reasoning under test-time compute scaling.
- This opens the possibility that selective parameter removal can be compatible with or supportive of scaling laws for reasoning.
Where Pith is reading between the lines
- If the claim holds, certain weights may interfere with optimal reasoning scaling and their removal could be net beneficial.
- The result suggests testing whether similar gains appear when unstructured pruning is combined with other compression techniques such as quantization.
- It raises the question of whether the effect generalizes to larger models or non-reasoning tasks.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper claims that unstructured pruning of reasoning LLMs (s1.1-7B and Qwen3-8B) can augment test-time scaling (TTS) performance on four reasoning benchmarks relative to structured pruning and, in some cases, even exceed the unpruned dense baseline. It further examines the role of layer-wise sparsity allocation strategies as a key hyperparameter for unstructured methods and concludes that carefully undertaken pruning can retain or improve TTS effectiveness, challenging prior assumptions about pruning degrading reasoning under test-time compute scaling.
Significance. If the empirical findings are robust, the result would be significant for efficient LLM deployment: it suggests that unstructured pruning need not trade off against TTS gains and could enable smaller models that match or surpass dense counterparts on reasoning tasks. The work provides new empirical comparisons across models and benchmarks with no reduction to author-defined fitted quantities.
major comments (3)
- [Abstract / Experiments] Abstract and experimental results: the headline claim that unstructured pruning 'at times can even outperform the unpruned full-weight LLMs' is presented without reported error bars, statistical significance tests, or controls for random seed variability, making it impossible to assess whether observed gains exceed noise (soundness concern noted in review).
- [Abstract] Abstract: the central result explicitly depends on 'carefully chosen layer-wise sparsity allocation strategies' described as 'an important parametric choice.' No ablation is described that isolates whether the TTS gains survive under non-tuned (e.g., uniform or random) per-layer densities; if the allocations function as an additional hyperparameter search compensating for pruning damage, the comparison to structured pruning and the dense baseline is not controlled.
- [Experiments] Experimental setup: the manuscript supplies no details on exact pruning implementations (e.g., which unstructured method, magnitude vs. other criteria), exact sparsity schedules, or how TTS is measured (number of samples, temperature, stopping criteria), preventing reproduction or assessment of confounds.
minor comments (1)
- [Abstract] Abstract: 'lays the foundation' should be 'lay the foundation' for subject-verb agreement.
Simulated Author's Rebuttal
We thank the referee for the constructive feedback highlighting areas where additional rigor and detail would strengthen the manuscript. We address each major comment below and commit to revisions where the current version is lacking.
read point-by-point responses
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Referee: [Abstract / Experiments] Abstract and experimental results: the headline claim that unstructured pruning 'at times can even outperform the unpruned full-weight LLMs' is presented without reported error bars, statistical significance tests, or controls for random seed variability, making it impossible to assess whether observed gains exceed noise (soundness concern noted in review).
Authors: We agree this is a valid soundness concern. The revised manuscript will report all key results with error bars computed over multiple random seeds and will include statistical significance tests (e.g., paired t-tests) to establish whether the observed gains over the dense baseline exceed variability. revision: yes
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Referee: [Abstract] Abstract: the central result explicitly depends on 'carefully chosen layer-wise sparsity allocation strategies' described as 'an important parametric choice.' No ablation is described that isolates whether the TTS gains survive under non-tuned (e.g., uniform or random) per-layer densities; if the allocations function as an additional hyperparameter search compensating for pruning damage, the comparison to structured pruning and the dense baseline is not controlled.
Authors: The manuscript already positions layer-wise allocation as a key hyperparameter and studies several strategies. To directly address whether gains persist without tuned allocations, the revision will add an explicit ablation comparing the reported tuned allocations against uniform and random per-layer sparsity on the same models and benchmarks. revision: yes
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Referee: [Experiments] Experimental setup: the manuscript supplies no details on exact pruning implementations (e.g., which unstructured method, magnitude vs. other criteria), exact sparsity schedules, or how TTS is measured (number of samples, temperature, stopping criteria), preventing reproduction or assessment of confounds.
Authors: We agree that reproducibility requires these details. The revised manuscript will specify the exact unstructured pruning criterion (magnitude pruning), the per-layer sparsity schedules, and the full TTS protocol (sample count, temperature, decoding strategy, and stopping criteria) in a dedicated experimental setup subsection. revision: yes
Circularity Check
No circularity: purely empirical comparisons with no derivation chain
full rationale
The paper reports experimental results from running unstructured and structured pruning on two LLMs across four reasoning benchmarks, measuring TTS performance. No equations, fitted parameters renamed as predictions, or self-citation load-bearing steps appear in the abstract or described content. Layer-wise sparsity allocation is explicitly called an 'important parametric choice' for the methods, but the headline claims rest on direct benchmark measurements rather than any reduction to those choices by construction. The work is self-contained against external benchmarks and contains no mathematical derivation that could be circular.
Axiom & Free-Parameter Ledger
read the original abstract
Large Language Models (LLMs) now exhibit remarkable reasoning capabilities through test-time compute scaling (TTS), with impressive performance across math and coding benchmarks. In parallel, research in model compression has developed pruning methods that seek to remove redundant/detrimental parameters without sacrificing task performance. The intersection of these two research advancements lays the foundation for our work. Specific to reasoning LLMs, prior work has shown that structured pruning (methods which remove entire set of layer blocks), significantly degrades TTS reasoning performance. However, in this work, we revisit this assumption and investigate whether unstructured pruning (methods that carefully remove only certain redundant/detrimental weights) exhibits similar limitations. Surprisingly, our extensive experiments across four reasoning benchmarks on two reasoning LLMs: s1.1-7B and Qwen3-8B, consistently show that unstructured pruning augments TTS performance compared to structured pruning, and at times can even outperform the unpruned full-weight LLMs. Furthermore, we also empirically study the impact of different layer-wise sparsity allocation strategies, which are an important parametric choice for instantiating these unstructured methods. These findings challenge the conventional notion that pruning always reduces TTS performance and in fact, suggest that carefully undertaken pruning can retain TTS effectiveness.
Figures
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Reference graph
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[8]
Then, find r2 where r is the radius of that sphere, and express it as a fraction p/q with p and q coprime, then find p+q . Al- right, let’s start. First, let me recall some formulas. For a rect- angular box with length, width, and height x, y, z, the surface area is2(xy+yz+xz) =
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[9]
The problem is about finding the smallest sphere that can contain such a box
The volume is xyz= 23 . The problem is about finding the smallest sphere that can contain such a box. The sphere’s radius will depend on the box’s dimensions. ..........= −1 + 2 √ 6≈ −1 + 4.898≈3.898 , which is positive. Therefore, if x=y= 2 , then z= 23/(22) = 23/4 = 5.75 . Alternatively, if x=y≈3.898 , then z= 23/x 2. Let me compute x2 exactly: x=−1 + 2 √
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[10]
There- fore, x2 = (−1+2 √ 6)2 = 1−4 √ 6+24 = 25−4 √ 6≈25−9.798≈15.202 . Then z= 23/(25−4 √ 6). Let me rationalize that denominator: Multiply numerator and denominator by (25 + 4 √ 6): z= 23(25+4 √ 6) (25−4 √ 6)(25+4 √
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[11]
Answer: 721 (Correct) 18 Table 12: Qualitative outputs on AMC23 for Unpruned vs
= 23(25+4 √ 6) 625−(4 √ 6)2 . Answer: 721 (Correct) 18 Table 12: Qualitative outputs on AMC23 for Unpruned vs. Wanda-Uniform 20% pruned model. Query Unpruned Wanda-Uniform 20% If A and B are vertices of a polyhedron, define the distance d(A, B) to be the minimum num- ber of edges of the poly- hedron one must tra- verse in order to con- nect A and B. For e...
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[12]
Find the probability that d(Q, R)> d(R, S)
Let Q, R, and S be randomly chosen dis- tinct vertices of a regu- lar icosahedron (regular polyhedron made up of 20 equilateral triangles). Find the probability that d(Q, R)> d(R, S) . The final answer can be written in the form m n , where m and n are rela- tively prime positive in- tegers. What is m+n ? Chain of Thought:Okay, so I need to find the maxim...
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[13]
Maybe there’s a better approach
Hmm, this seems complicated. Maybe there’s a better approach. Let me think. Al- ternatively, maybe consider substituting y2 from the equation or something else. Alter- natively, think of this as a quadratic equation in y2? Let me check. Let me rearrange the equation: y4 + (2x2 + 2x−1)y 2 + (x4 + 2x3 + 3x1 + 2x+ 1−16) = 0 . So, if I let y2 =t , then:t2 + (...
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[14]
Can we make 29 with 6 and 10? 29 is odd. 6 and 10 are even. So no. If we use 15 twice: 44 - 30 = 14. Can we make 14 with 6 and 10? 10 + 6* (something)? 14 -10 = 4. Not divisible by 6. 14 - 6 = 8. Not divisible by 10. So no Answer: 8 (Incorrect) Chain of Thought:Okay, so I need to fig- ure out the largest amount of money that can’t be formed using coins of...
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[15]
The positions that are meta to 1 are 3 and
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[16]
The positions that are meta to 3 are 1 and
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[17]
A benzene ring has a carboxylic acid, a carbaldehyde, and a cyano group all meta to one another
Therefore, the only common position is 5. So if the third group is at 5, then it is meta to both 1 and 3. Therefore, the three groups are at positions Answer: C (Incorrect) Chain of Thought:Okay, so I need to figure out the correct IUPAC name for this com- plex benzene ring molecule. Let me start by breaking down the information given. First, the molecule...
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[18]
So, to have the addition happen earlier, we need to have parentheses that include the ad- dition operator. But the addition is between the product and 1, so how can we group it differently? Wait, for example, maybe insert- ing parentheses between the multiplications and the addition. For example, 2·3·(4·(5 + 1)) which is same as before. Or 2·(3·4·(5 + 1))...
work page 2048
This paper was first reviewed by grok-4.3 on July 1, 2026.
discussion (0)
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