Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
DeepSeek V4 Flash Base
31
GPT-5.4 Pro
91
Pick GPT-5.4 Pro if you want the stronger benchmark profile. DeepSeek V4 Flash Base only becomes the better choice if knowledge is the priority or you would rather avoid the extra latency and token burn of a reasoning model.
Reasoning
+38.6 difference
Knowledge
+3.2 difference
DeepSeek V4 Flash Base
GPT-5.4 Pro
$null / $null
$30 / $180
N/A
74 t/s
N/A
151.79s
1M
1.05M
Pick GPT-5.4 Pro if you want the stronger benchmark profile. DeepSeek V4 Flash Base only becomes the better choice if knowledge is the priority or you would rather avoid the extra latency and token burn of a reasoning model.
GPT-5.4 Pro is clearly ahead on the provisional aggregate, 91 to 31. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.4 Pro's sharpest advantage is in reasoning, where it averages 83.3 against 44.7. DeepSeek V4 Flash Base does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
GPT-5.4 Pro is the reasoning model in the pair, while DeepSeek V4 Flash Base is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.4 Pro gives you the larger context window at 1.05M, compared with 1M for DeepSeek V4 Flash Base.
GPT-5.4 Pro is ahead on BenchLM's provisional leaderboard, 91 to 31.
DeepSeek V4 Flash Base has the edge for knowledge tasks in this comparison, averaging 52.2 versus 49. GPT-5.4 Pro stays close enough that the answer can still flip depending on your workload.
GPT-5.4 Pro has the edge for reasoning in this comparison, averaging 83.3 versus 44.7. DeepSeek V4 Flash Base stays close enough that the answer can still flip depending on your workload.
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