Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.4 mini
71
Qwen3.5-27B
63
Verified leaderboard positions: GPT-5.4 mini unranked · Qwen3.5-27B #16
Pick GPT-5.4 mini if you want the stronger benchmark profile. Qwen3.5-27B only becomes the better choice if knowledge is the priority or you want the cheaper token bill.
Agentic
+14.0 difference
Knowledge
+23.2 difference
GPT-5.4 mini
Qwen3.5-27B
$0.75 / $4.5
$0 / $0
201 t/s
N/A
3.85s
N/A
400K
262K
Pick GPT-5.4 mini if you want the stronger benchmark profile. Qwen3.5-27B only becomes the better choice if knowledge is the priority or you want the cheaper token bill.
GPT-5.4 mini is clearly ahead on the provisional aggregate, 71 to 63. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.4 mini's sharpest advantage is in agentic, where it averages 65.6 against 51.6. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 60% to 41.6%. Qwen3.5-27B does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
GPT-5.4 mini is also the more expensive model on tokens at $0.75 input / $4.50 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Qwen3.5-27B. That is roughly Infinityx on output cost alone. GPT-5.4 mini gives you the larger context window at 400K, compared with 262K for Qwen3.5-27B.
GPT-5.4 mini is ahead on BenchLM's provisional leaderboard, 71 to 63. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 60% and 41.6%.
Qwen3.5-27B has the edge for knowledge tasks in this comparison, averaging 80.6 versus 57.4. Inside this category, GPQA is the benchmark that creates the most daylight between them.
GPT-5.4 mini has the edge for agentic tasks in this comparison, averaging 65.6 versus 51.6. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
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