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BenchLM
Data

Quasar 438B vs Step 5 Preview

Updated November 5, 2026. We do not rank this pair: at least one has no public score. Public scores include evidence status and uncertainty.

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Decision reading

At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner. 2 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
Quasar 438B

Multiverse Computing

—

Evidence status unavailable

90% interval unavailable

Model B
StepFun logo
Step 5 Preview

StepFun

56.81/100

Estimated · Public rank #60

Conditional range 47.1–66.5

Shared results
2
Quasar 438B only
0
Step 5 Preview only
22
Like-for-like categories
0 / 8
Estimated: Step 5 Preview. Conditional ranges do not establish rank confidence.How the comparison works

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Chat turn cost

    1K fresh input + 500 output tokens

    Quasar 438B

    Quasar 438B has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    Step 5 Preview

    Step 5 Preview has the lower estimated token cost for this stated workload. Quasar 438B has no published cached-input rate, so cached tokens use its listed input rate.

    Confidence: rate-fallback
Show secondary and unsupported calls

  • Repository review cost

    50K fresh input + 3K output tokens

    Quasar 438B

    Quasar 438B has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Coding work

    Code generation, repair, and software-engineering tasks

    Not enough matched evidence

    Quasar 438B and Step 5 Preview are scored on Estimated evidence for coding, so the reading is directional rather than like-for-like.

    Confidence: limited

  • Agentic work

    Tool use, computer use, and multi-step task completion

    Not enough matched evidence

    Quasar 438B and Step 5 Preview are scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.

    Confidence: limited

  • Long documents

    Prompts that approach the documented context limit

    No clear pick

    The documented context windows are equal.

    Confidence: documented

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

39.8Quasar 438B48.8Step 5 Preview

Directional only · BenchAlign v5.8

Step 5 Preview has the higher coding point estimate. Conditional score ranges do not establish rank confidence.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Open the coding leaderboardShortlist models for this job
Same basis rules as the category table below

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

2 categories rest on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

A shared-evidence shape is not available.

BenchLM does not draw a radar or infer missing axes when the matched evidence is too sparse.

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.8 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Agentic

Directional only
Quasar 438B
39.6
Estimated · #76/135
Step 5 Preview
55.3
Estimated · #42/135
Basis
BenchAlign v5.8 lane · 1 vs 13 public rows
Reading
Directional only

Coding

Directional only
Quasar 438B
39.8
Estimated · #70/156
Step 5 Preview
48.8
Estimated · #47/156
Basis
BenchAlign v5.8 lane · 1 vs 6 public rows
Reading
Directional only

Reasoning

Not comparable
Quasar 438B
77.4
Unranked · 2 rankable rows
Step 5 Preview
82.5
Unranked · 2 rankable rows
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Multimodal

Not comparable
Quasar 438B
Not ranked
Step 5 Preview
73.3
#32/58
Basis
Provisional lane · 0 vs 2 weighted rows
Reading
Not comparable

Knowledge

Not comparable
Quasar 438B
Not ranked
Step 5 Preview
61.0
Supported · #44/177
Basis
BenchAlign v5.8 lane · 0 vs 2 public rows
Reading
Not comparable

Multilingual

Not comparable
Quasar 438B
Not ranked
Step 5 Preview
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
Quasar 438B
Not ranked
Step 5 Preview
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
Quasar 438B
Not ranked
Step 5 Preview
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.8) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

Quasar 438B
$0.0015
Fits in one request
Step 5 Preview
$0.00235
Fits in one request

Quasar 438B has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

Quasar 438B
$0.0354
Fits in one request
Step 5 Preview
$0.0581
Fits in one request

Quasar 438B has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

Quasar 438B
$0.15
Fits in one request
Cached input priced at the published list-input rate
Step 5 Preview
$0.057
Fits in one request

Step 5 Preview has the lower modeled cost

Quasar 438B has no published cached-input rate, so cached tokens use its listed input rate.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Reasoning profile

Quasar 438B

Reasoning

Step 5 Preview

Reasoning

Weight access

Quasar 438B

Proprietary

Step 5 Preview

Open Weight

License

Quasar 438B

Proprietary

Step 5 Preview

Open Weight

Release date

Quasar 438B

2026-09-02

Step 5 Preview

2026-09-20

If you already use one of these models

Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner.
Workload cost
Repository review: $0.0354 vs $0.0581. Cache-heavy agent loop: $0.15 vs $0.057.
Context tradeoff
Both models list 1M.
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, Quasar 438B or Step 5 Preview?

At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, Quasar 438B or Step 5 Preview?

Step 5 Preview scores higher for coding on the public lane, 48.8 to 39.8. Quasar 438B and Step 5 Preview are scored on Estimated evidence for coding, so the reading is directional rather than like-for-like. BenchLM does not name a winner for coding from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which is better for agentic tasks, Quasar 438B or Step 5 Preview?

Step 5 Preview scores higher for agentic tasks on the public lane, 55.3 to 39.6. Quasar 438B and Step 5 Preview are scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which costs less, Quasar 438B or Step 5 Preview?

For the stated presets, chat costs $0.0015 on Quasar 438B and $0.00235 on Step 5 Preview; repository review costs $0.0354 and $0.0581; the cache-heavy agent loop costs $0.15 and $0.057. Quasar 438B has no published cached-input rate, so cached tokens use its listed input rate.

Which has the larger context window, Quasar 438B or Step 5 Preview?

Both models list the same context window, 1M.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Quasar 438B
API / mo$1,800
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Step 5 Preview
API / mo$2,775
Self-host / mo$27,962
Break-even617M/day
Model the full break-even

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence24 rows

Agentic

  • Terminal-Bench 2.1

    Quasar 438B69.3%
    Source
    Step 5 Preview85.0%
    Source

    Step 5 Preview leads this result

  • Terminal-Bench 4.0

    Quasar 438B—
    Step 5 Preview33.30%
    Source

    Not directly comparable

  • CyberGym

    Quasar 438B—
    Step 5 Preview84.7%
    Source

    Not directly comparable

  • AutomationBench

    Quasar 438B—
    Step 5 Preview44.0%
    Source

    Not directly comparable

  • Toolathlon-Verified

    Quasar 438B—
    Step 5 Preview74.1%
    Source

    Not directly comparable

  • MCP Atlas

    Quasar 438B—
    Step 5 Preview85.6%
    Source

    Not directly comparable

  • JobBench

    Quasar 438B—
    Step 5 Preview59.0%
    Source

    Not directly comparable

  • APEX-Agents

    Quasar 438B—
    Step 5 Preview37.8%
    Source

    Not directly comparable

  • DRACO

    Quasar 438B—
    Step 5 Preview83.3%
    Source

    Not directly comparable

  • BrowseComp

    Quasar 438B—
    Step 5 Preview88.7%
    Source

    Not directly comparable

  • Agents' Last Exam

    Quasar 438B—
    Step 5 Preview29.5%
    Source

    Not directly comparable

  • Hermes Index

    Quasar 438B—
    Step 5 Preview32.8%
    Source

    Not directly comparable

  • Hermes Bench

    Quasar 438B—
    Step 5 Preview69.2%
    Source

    Not directly comparable

Coding

  • Terminal-Bench 2.1

    Quasar 438B69.3%
    Source
    Step 5 Preview85.0%
    Source

    Step 5 Preview leads this result

  • DeepSWE

    Quasar 438B—
    Step 5 Preview67.7%
    Source

    Not directly comparable

  • SciCode

    Quasar 438B—
    Step 5 Preview58.9%
    Source

    Not directly comparable

  • ProgramBench

    Quasar 438B—
    Step 5 Preview80.5%
    Source

    Not directly comparable

  • sweMarathon

    Quasar 438B—
    Step 5 Preview72.7%
    Source

    Not directly comparable

  • MLS-Bench Lite

    Quasar 438B—
    Step 5 Preview40.5%
    Source

    Not directly comparable

Reasoning

  • CritPt

    Quasar 438B—
    Step 5 Preview20.9%
    Source

    Not directly comparable

Multimodal

  • OfficeQA Pro

    Quasar 438B—
    Step 5 Preview60.3%
    Source

    Not directly comparable

  • MMMU-Pro

    Quasar 438B—
    Step 5 Preview76%
    Source

    Not directly comparable

Knowledge

  • GPQA-D

    Quasar 438B—
    Step 5 Preview93.5%
    Source

    Not directly comparable

  • HLE

    Quasar 438B—
    Step 5 Preview46.5%
    Source

    Not directly comparable

24 public results · 2 shared

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Last updated November 5, 2026