GLM 5.2 costs most in VulcanBench
VulcanBench creator Morgan Linton shared results comparing GLM 5.2, Claude Opus 4.8, and GPT-5.5 across 52 coding tasks. Despite lower advertised per-token pricing, GLM 5.2 was the most expensive and slowest model tested due to its high thinking-token generation.
Raw API pricing is a deceptive metric for reasoning models with 'thinking' steps. While GLM 5.2 has low per-token pricing on paper, its agentic loops generate massive token volumes and high latency that make it less competitive for developer workflows.
- –**Thinking Token Inflation:** Reasoning-focused models like GLM 5.2 generate large numbers of internal thinking tokens, which rapidly accumulate costs during multi-turn coding agent tasks.
- –**Latency Bottleneck:** An average task execution time that is 3.3x slower is a major productivity blocker for developers expecting fast interactive loops in IDEs.
- –**Benchmark Realism:** The comparison on VulcanBench's 52 tasks highlights why real-world agent evaluations are necessary, as paper-thin token pricing does not map linearly to end-user costs.
- –**Enterprise Implications:** Teams standardizing on open-weights reasoning models for agentic pipelines need to monitor total session costs and execution times, not just baseline token input/output rates.
DISCOVERED
1h ago
2026-06-25
PUBLISHED
2h ago
2026-06-25
RELEVANCE
AUTHOR
morganlinton