Top
Best
New

Posted by Liwink 1 day ago

DeepSeek v4.1 Flash(twitter.com)
https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash
974 points | 554 commentspage 3
karimf 1 day ago|
While this is very impressive benchmark-wise, GPT-6 Astra showed us that benchmarks don't always correlate 1:1 to intelligence of a model.

When Astra launched, I think Artifical Analysis showed that it was on par with GPT-5.6 Sol and lower than Opus or something like that? Then, they updated the scoring.

I hope that more open source models, including this model, to be "as good to use" as Astra.

walrus01 1 day ago||
Apparently the scoring on a lot of difficult benchmarks can also be extremely influenced by something as simple as waiting for the model to exhaust its reasoning, realize it hasn't come to a conclusion yet, and give it a simple prompt like "you can do this, I know you're capable, please keep going".
Squarex 1 day ago||
I don't know why, but the benchmarks still fails to cover the difference between large models and small ones. The small ones are great for many things, including general coding, but the larger ones, like fable and astra, have some kind of intelligence that is not present in the small ones.
sinuhe69 1 day ago||
More parameters = more facts stored. Knowledges are almost incompressible, where strong reasoning only requires a 3B core or so.
yorwba 1 day ago||
Weibo's VibeThinker manages with half of that: https://arxiv.org/abs/2511.06221 (They finetuned Qwen2.5-Math-1.5B for reasoning.)
Tepix 1 day ago||
Amazing Cyberbench scores. Holy shit.

Too bad that DeepSeek AI went beyond 470b weights (which is a somewhat realistic limit for a 2x 128GB unified memory machine cluster like Strix Halo or Nvidia Spark).

That means that to make the model fit into memory there you need a quantisation of lower than 4bits per weight (which is usually bad) to fit it into the available memory.

pvab3 22 hours ago|
what would happen if you ran it off the SSD? Would it just wear it out or take weeks to run a simple prompt?
Tepix 20 hours ago||
I'm sure that it will work, but tokens/s will suffer quite a bit. You may still be able to get 10t/s or so..
NitpickLawyer 1 day ago||
Jesus, this is a whole nother beast, and a different architecture from their previous flash. Lots of goodies here.

> Causal Encoder-Decoder (CED) architecture: a 40-layer Transformer organized as a 20-layer causal encoder followed by a 20-layer decoder. With CED, the decoder's global KV cache is projected from the final encoder hidden states rather than derived from each decoder layer's own hidden states. This allows the model to activate only 8B parameters per token during prefill and 16B during decode, substantially improving cost efficiency for input-heavy agentic workloads.

> these designs reduce the global KV cache footprint to 890 bytes per token — roughly 1/4 of DeepSeek-V4-Flash.

Faster prefill, lower kv cache (~1GB / 1m context is insane).

> The model supports a continuously controllable reasoning effort setting (integer 1–100) that trades inference cost for accuracy.

Benchmarks are benchmarks, to be seen if they translate to real-world use, but they seem to have focused a lot on post-training with "agentic" scores looking good. "world knowledge" is obviously lower than higher param models.

k__ 1 day ago||
So, while the throughput was 400-500tps in beta its now ~150tps on OpenRouter.

I was hoping for a bit more, but it's still 100% faster for a very good price, so I won't complain.

k__ 22 hours ago|
Update:

I'm using it right now and it's noticeably faster.

I'd also say, it seems smarter, but I think that's because of some harness updates I installed. (I haven't used pi for almost a month)

E-Reverance 1 day ago||
The figure on page 5 in [1] is pretty insane

[1] https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash/blob/...

walrus01 1 day ago||
Looking at the huggingface page, the unsloth people haven't finished quantizing it yet, but I'm sure they're active on it right now. It'll be interesting to see how the capabilities and benchmark tests compare on system where it can fit in under 512GB of RAM with full context.

In terms of coding and command line capabilities I'm also very interested to see a head-to-head of it vs. qwen 3.8-flash-next Q8 which is something like 190GB of memory used when loaded into llama-server. It fits very well in all sorts of 256GB or under class machines.

lowbloodsugar 18 hours ago|
3.8-flash-next fits on a single 6000 at Q4 if you offload the PLE. Crazy fast and still effective.
agile-gift0262 16 hours ago||
Sorry for the tangent, but how does Qwen3.8-flash-next compare to DeepSeek v4 Flash? I still haven't found the time to set it up, but I'm really happy with DeepSeek v4 Flash
lowbloodsugar 12 hours ago||
It was the best model given my constraints (RTX PRO 6000 96gb + 256GB DDR4), when run against rust programming benchmarks. For Qwen3.8-flash-next NVFP4 and the latest vllm container, the PLE is 100GB of main ram, and everything else runs on the GPU with room for a total of 560k tokens (two full 262k conversations). DeepSeek has to offload a ton to the CPU and it performed worse than Qwen in absolute terms and was a lot slower (not usable).

If you have enough room to run DeepSeek v4 Flash comfortably then you can likely run the Q8 of the qwen model.

dang 20 hours ago||
Prequel thread:

DeepSeek launching v4.1 flash cheaper and more capable than v4 pro - https://news.ycombinator.com/item?id=49624603 - Sept 2026 (216 comments)

Alifatisk 1 day ago||
> New Causal Encoder–Decoder architecture: just 8B active parameters for input, 16B for output.

Oh interesting, I can assume what the benefits is for including the Encoder, but whats the downside? I’m thinking GPT (which is decoder only) ruled out Encoder for a reason?

Alpha3031 1 day ago|
Enc-decs are usually harder to train at frontier scale. Not 100% sure what DeepSeek has done differently here initial read seems to be something related to layer reuse but I just skimmed things so far.
abecode 17 hours ago||
yes, that was surprising to me too. It would be a big deal if they switched to an encoder-decoder model like the original transformer. But I don't think that's what it's doing. One thing is the causal part, so in the original transformer, the encoder was bidirectional, but in this case it is not, so that's one difference. So I think it's an optimization for the prompt/prefill so that the attention is summarized into the output of the encoding layers, rather than all the layers. I just skimmed the paper too so if anyone else has insight, please correct me.
a012 1 day ago||
Waiting this model to be on openrouter (with other providers) to test out. In my use case, the GLM 5.3 Flash is the current cheapest and intelligent Flash model, but it’s dog slow at 13tps so I have to leave it run for many minutes then check again then correct it again
drob518 1 day ago|
The speed of GLM 5.3 Flash on OpenRouter seems to vary considerably by provider. Some are fast and some are slow. OpenRouter does provide some tuning knobs, but not enough for my taste. It’s also token-heavy with reasoning, though I found it better than Deepseek V4 Flash previously.
shunia_huang 1 day ago||
> though I found it better than Deepseek V4 Flash previously

Same experience here.

But man, switch to V4.1 now! It is much better.

I don't event need to test it for long run and I believe it's crazy good. I call it "AI era model taste" when I judge the model by it's output without reading the bench scores.

a012 22 hours ago||
I’ve just tried, it’s now my new favorite Flash model
schneehertz 1 day ago|
A very powerful model, and with multimodal support now, it can be used as a primary model.
More comments...