DeepSeek V4.1 Flash hands-on tests and comparisons

A user complains vLLM merges PRs for non-mainstream setups too slowly, citing V4.1 Flash being completely broken and unable to start on 4x RTX 6000 Pro with mainline vLLM.

The author wired DeepSeek V4.1 Flash into Wally as ghost-text autocomplete and says it is fast enough to write whole functions before the finger leaves Tab, with a demo video.

Local DeepSeek-V4.1-Flash at ISTA-DAS 2.25 bpw on one RTX 5090: 47 tok/s long generation and 1,400 tok/s prefill, beating Project Maya on the same box.

After the price hike, running DeepSeek V4.1 Flash at max effort inside an agent costs tens of yuan a day and 1,000–2,000 a month, the poster says.

The user says Astra got nerfed, so they went back to Opus 5.5, Fable 5.1 and the latest DeepSeek V4.1 Flash.

The author used Hermes agent with DeepSeek V4.1 Flash 1017 via Venice to replace their Amazon smart TV homepage with a custom dashboard and block adware, noting the local connection setup was most of the work.

A user pushes back on the idea that only small 4-bit quants run locally, saying the full native quant of DeepSeek V4.1 Flash 1017 runs at solid speeds across 4x DGX Sparks.

A commenter finds the comparison of DeepSeek V4.1 Flash 1017 to a nonexistent Opus 5.3 wild, while acknowledging the current hype around open-weight models.

A subjective comparison placing DeepSeek V4.1 Flash 1017 at roughly the level of a hypothetical Opus 5.3, without benchmark data.

The author spent $26.80 in tokens using both models to build a PoC for CVE-2026-111497 across 84 builds, noting 58.3% of 14,877 exploit attempts crashed the lab.

Lithos AI co-designs engine, kernels and compiler to hit 2,100+ tok/s/user for DeepSeek V4.1 Flash at full quality on 8× AMD MI355X, 2.8× faster than existing open-source stacks.

A user ran the same SVG animation prompt on Qwen 4 Kerria and DeepSeek V4.1 Flash, saying Qwen clearly wins and may even be Qwen 4 Max.