DeepSeek v4.1 Flash Benchmark: Testing a 1M Context LLM Route

Large context window models have become essential for building AI agents, document pipelines and code analysis tools. While exploring options for my internal workloads, I set up a direct route for DeepSeek v4.1 Flash and ran a simple benchmark to record latency, success rate and operational cost. I’m sharing these observations for anyone else evaluating long-context LLMs.

Model Overview

DeepSeek v4.1 Flash supports a 1M-token context window with an unusually high maximum generation limit of 393K tokens.…