DeepSeek V4.1 Flash hands-on tests and comparisons

An all-day agent operator says DeepSeek's newer model is stronger, answers more concisely and costs less, and that for heavy agent users the actual bill matters more than benchmark scores.

The author argues OpenCode's 24h call volume reflects real engineering usage where V4.1 Flash leads on low latency, while Agent Arena measures quality ceiling, and suggests comparing pass@k against end-to-end latency on the same projects.

Five observations: most users may not need it, benchmark scores stay within noise of the original, differences show on edge cases, an MLX build runs on a 256GB Mac, and some endpoints charge 3–4x.

Cline 4.1.26 fixes Gemini free-tier 429s and dropped tools on Gemini 2.x, cuts retries from 5 to 3, and shifts most provider defaults to Kimi K3.1 Pro, MiniMax M3.1 Flash or DeepSeek V4.1 Flash 1017.

A user notes DeepSeek V4.1 Flash dominates OpenCode's 24-hour call volume while Kimi K3.1 Pro, ranked first among open models on Agent Arena, sees almost no use, questioning the gap between benchmarks and practice.

Running DeepSeek V4.1 Flash 1017 at GSQ-RCO IQ2XS quantization on a 7900 XTX with 60GB DDR5 yields 10 tps decode and 800 tps prefill, with 200k context under an FP4 KV cache.

Suggests running DeepSeek-V4.1-Flash-1017 locally on a single DGX Spark alongside GLM-5.3 Flash and Qwen3.8-Flash-Next, possibly covering everything locally.

Running DeepSeek V4.1 Flash as a Blender worker under Opus 5.5 orchestration cost about $34 over 52.6 hours, roughly ¥20 per task, with 51 of 55 miura-fold roof tasks passing Opus review, though hard spots still needed Opus.

The community ran a head-to-head benchmark of vLLM DEP32 against DeepSeek's in-house DeepInfer framework, measuring decoding performance on DeepSeek-V4.1-Flash-1017.

A user complains that running OpenCode with DeepSeek V4.1 Flash as the sole fallback model consumed a large share of quota in under three days.

The MIT-licensed Strata 0.2.6 runs V4.1 Flash at IQ2_XXS on a 16GB RTX 4080 Super with 128GB RAM, lifting generation from 10 to 16.7–22.7 tok/s and doubling prefill.

A 2.25bpw quant of DeepSeek V4.1 Flash on an OCuLink RTX 5060 Ti 16GB reaches 7.6 tok/s and finishes a pagoda task in 77 minutes, matching quality but about 4x slower than the comparison model.