DeepSeek V4.1 Flash hands-on tests and comparisons

On one 4090/48G, stock Maya-XS with no patches pushes DeepSeek V4.1 Flash to 65 tok/s code generation (72.4 peak) and cuts 16K first-token latency from 23.5s to 8.6s.

Artificial Analysis switched its coding index to Cognition's FrontierCode: V4.1 Flash in Codex takes second at 52.6% behind Opus 5.5 in Claude Code at 56.0%, at $0.39 versus $11.42 per task.

Same prompt, harness and reasoning effort: DeepSeek's platform finished in 45m38s with 99.7% cache hits, while OpenCode Go took 3h25m with 96%.

MiniMax released its 428B-parameter MoE M3.1 Flash, claiming 70% lower agent cost; it scores 73.7% on DeepSWE v1.1, trailing DeepSeek V4.1 Flash-1017's 77%.

Seven local AI agent experiments using Qwen3.8-27B and DeepSeek-V4.1-Flash, from a 16GB consumer GPU to 512GB RAM systems, aimed at browser-explorable generated worlds.

RunAnywhereAI adds fast versions of DeepSeek V4.1 Flash, GLM-5.3 and DeepSeek V4 Pro, aimed at agent loops, voice and other latency-sensitive uses.

On one workstation, code hits 502 tok/s with 6.1 tokens per step and 76% draft acceptance, while prose gets 211 tok/s at 2.1 tokens and 39%, showing spec-decoding numbers depend on prompt type.

A user notes V4.1 Flash 1017 ranks among the best in absolute performance on a cybersecurity benchmark while costing about 50x less than Astra, crediting architecture like engram.

The author calls V4.1 Flash an Opus 5-level open model at a fraction of the cost, and worries pairing it with ARTEX-style pentest tools enables rapid-fire vulnerability scanning, possibly tied to an October rise in incidents.

The poster notes Codex with DeepSeek V4.1 Flash costs $0.39 per task and scores 52.6% on FrontierCode, just below Opus, which costs $11 per task.

A user says DeepSeek-V4.1-Flash-1017 is very good but has a Claude-like habit of inventing hidden requirements in prompts instead of following what was said.

The author skipped DeepSeek Harness for 24 hours, rotating free V4.1 Flash access across Qoder (free until Oct 24), WorkBuddy (extended to Oct 31) and OpenCode (free with rate limits).