Scope

• Model tested: deepseek/deepseek-v4-flash
• Total tests: 459
• Categories: All categories were included (no category filter applied)
• Run mode: Full run (not limited or partial), though results are truncated in output
• Fail-fast mode: Disabled (fail_fast=false)

Performance Summary

• Pass rate: 226/459 (49.2%)
• Score: 2234.12 out of 3137 (71.2% of max)
• Total cost: $0.0577
• Latency:
  • Average: 9.98s
  • Median: 5.88s
  • Average TTFT (Time to First Token): 1.25s
• Output speed: 52.44 tok/s average

Category-Level Performance

High-Performing Categories

• Speed: 55/60 passed (91.7%), 96.1% score — fastest TTFT (0.71s) and high output speed (60.96 tok/s)
• Cost: 29/30 passed (96.7%), 87.3% score — excellent accuracy and low cost
• Coding: 48/60 passed (80%), 92.3% score — strong in easy and hard levels, weakest in medium (65% pass)
• UI: 6/9 passed (66.7%), 79.1% score — limited data, but moderate performance

Low-Performing Categories

• Refactoring: 9/60 passed (15%), 61.0% score — very low pass rate despite decent score percentage
• Security: 11/60 passed (18.3%), 58.2% score — poor pass rate across all levels
• Reasoning: 14/60 passed (23.3%), 69.1% score — struggles with constraint and runtime correctness logic
• Debugging: 25/60 passed (41.7%), 71.9% score — inconsistent, with some complex failures (e.g., prototype pollution parsing error)

Hallucination

• Pass rate: 29/60 (48.3%), 72.5% score
• Mixed results: passes on real APIs (e.g., fetch-timeout, node-crypto) but fails on common misconceptions (e.g., array-flat, promise-resolve)
• Notable failure: halluc-edge-string-truncate took 90.73s with very low output speed (1.16 tok/s)

Notable Observations

• Failures due to parsing errors:
  • Two debugging tests (prototype-pollution-check-v2, prototype-pollution-merge-v2) failed with error: Spread syntax requires ...iterable[Symbol.iterator] to be a function — likely model generated invalid JS syntax.
• High-latency outliers:
  • debugging::deep-clone-v2: 68.95s latency (TTFT: 38.64s)
  • halluc-edge-string-truncate: 90.73s latency (TTFT: 0.92s, but output speed only 1.16 tok/s)
• Cost-efficient categories: cost had lowest total cost ($0.0011) despite high pass rate
• High-cost categories: refactoring ($0.0136) and reasoning ($0.0085) due to longer outputs and retries

Conclusion

The deepseek/deepseek-v4-flash model performs well in coding, cost, and speed tasks, showing fast response times and high accuracy. It struggles significantly in refactoring, security, and reasoning, indicating weaknesses in deeper program analysis and logical deduction. Hallucination resistance is moderate, with frequent false claims about API behavior. Latency is generally acceptable, though a few pathological cases (e.g., string truncation, deep clone) show severe performance degradation.