DeepSeek V4.1 Flash hands-on tests and comparisons

The author open-sources deepseek-bot, a self-hosted personal agent on DeepSeek Harness with memory, a messenger gateway and a TUI, running the ultrafast DeepSeek V4.1 Flash model.

On a trading-system coding task, DeepSeek V4.1 Flash High failed after about 15 improvement loops while GPT-6 Sol xhigh solved it in one shot, though the poster notes it is a single case.

Same prompt, two procedural turbofans: DeepSeek V4.1 Flash 1017 vs MiniMax M3.1 Flash compared on explode-hold-reassemble spatial math.

DeepSeek open-sources DeepInfer, the inference engine behind its production traffic, defaulting to V4.1-Flash-1017 with DSpark speculative decoding, EPLB and support for SM100 and Ascend 950.

A practitioner lists agent setup tips such as Cloudflare Zero Trust auth, a dedicated email and capped credit card, and routing quick responses to DeepSeek V4.1 while falling back to Opus or Astra for deeper reasoning.

Runware now hosts DeepSeek-V4.1-Flash-1017 with text and image input, tool calls, streaming, 1M context and output, priced at $0.15/1M input and $0.60/1M output.

DeepSeek released DeepInfer, the framework it says serves V4.1-Flash in production, with optimized kernels, speculative decoding, and parallelism setup, but it supports only that model on Nvidia SM100 or Huawei Ascend 950 and omits KV cache, prefill/decode split, and load balancing.

Open recipe runs DeepSeek V4.1 Flash on four CMP 170HX cards: 296 tok/s structured for one user, 796 tok/s aggregate for eight, 1M context, with 189 GiB Engram tables streamed from NVMe.

An inference benchmark of DeepSeek V4.1-Flash-1017 in Sparkline with 65,536-token prompts, 512-token outputs, concurrency 1 and 20 requests.

Ant Group and the vLLM community open-sourced the Humming quantized-inference kernel library; swapping V4.1 Flash's MoE to W4A8 raised throughput 14–43% and cut first-token latency about 30% on 8 H20 GPUs.

A per-domain AI recommendation list names Claude Opus 5.5 for coding and DeepSeek V4.1 Flash 1017 as the low-cost coding option, alongside picks for multimodal, image, and video tools.

On the same Three.js jet-engine prompt, DeepSeek V4.1 Flash 1017 took ~1h30m with strong detail but huge token burn, Opus 5.5 1h19m, and GPT-6.1 Sol 26m57s.