DeepSeek V4.1 Flash hands-on tests and comparisons

A walkthrough for adding a plugin to DeepSeek Harness so DeepSeek V4.1 Flash, GLM 5.3 Flash and Kimi K3 appear in the model picker for free, with no login or API key, subject to region and lineup.

The poster burned 860M V4.1 Flash tokens in 3.5 hours, 154M of them on a custom IDE, and used the model inside a Windows VM to take apart Diablo IV.

Using P/D disaggregation and Wide-EP on a GB300 NVL72 rack, vLLM serves V4.1-Flash on SemiAnalysis AgentX at 954K tokens/s per GPU with 196 tokens/s P90 per user, 7.9x its single-node result.

Strata's terminal build bundles V4.1 Flash and serves a local OpenAI/Anthropic API; on a 12GB RTX 5070 with 64GB RAM, Q2_0 hits 94 tok/s and IQ3_S 53 tok/s, with prompt intake around 2,650 tok/s.

A solo non-CS developer splits a Ghostty terminal into four panes via Herdr and OMP: Opus 5.5 dispatches, V4.1 Flash 1017 Max writes code, Sol and Astra escalate and review; cost savings are not yet measured.

Qoder users can use DeepSeek V4.1 Flash 1017 free through November 1, with Qwen3.8-Flash free indefinitely and 100 daily credits for GLM 5.3, Kimi K3.1 Pro and others.

From limited input the author finds V4.1 Flash the best conversational model, agreeing that GPT-6.1 Sol often sounds forced and trained to be relatable.

A user posts that among providers tried, Ollama is the fastest for DeepSeek V4.1 Flash, without giving concrete tok/s figures.

A CMU researcher says he bought a B300 for LLM research but is now considering serving DeepSeek V4.1 Flash tokens with DeepSeek's new inference code to fund the rest of his lab.

A user runs EXL3 2.9bpw DeepSeek V4.1 Flash on four DGX Sparks via TensorFold TP4, hitting ~155 tok/s code and ~87 prose at 1M context with 16 streams, and lists four setup gotchas.

Pricing 7 days of real Claude Code logs (5.1B tokens) per model gives $1,965 for Opus 5.5, $983 for Sonnet 5.5, $620 for Gemini 4 Argon, $74 for Haiku 5.5 and $44 for DeepSeek V4.1 Flash, about 45x cheaper, though the author concedes quality differs.

The user says GLM-5.3-Flash feels like a practical, production-ready model while DeepSeek-V4.1-Flash still feels experimental, and reports using Maya with GLM daily.