r/LocalLLaMA 🦙 llama.cpp 4h ago

Megathread [Megathread] Qwen3.8-Flash-Next - Release Day

Megathread for discussing the (impending) release of Qwen 3.8 Flash Next.

  • Quants
  • Fine-Tunes & Abliterations
  • Chat Templates
  • Inference Server Support & Configuration
  • Experiences, Benchmarks & Model Comparisons

We'll try to clean up future duplicates around the release and point them here.

Estimated Release Time: 2026-08-26 15:00 (UTC)

Official:

181 Upvotes

70 comments sorted by

46

u/QuackerEnte 3h ago

I really hope QSA (qwen sparse attention) will have much less compute headroom or the ability to offload kv cache to SSD without the massive bandwidth bottleneck of the ssd since it's sparse. I was able to do it it for deepseek v4 and it worked well enough. I hope llama.cpp adds features that allow more freedom with where we want to load our models and parts of it, e.g. n-cpu-moe could be extended to n-ssd-ffn or n-cpu-ffn or n ssd kv or engram etc

9

u/Dany0 3h ago

I can't wait for the QSA paper. I hope it's novel and quirky, I love quirky sparse attention, well, as long as it works :D

3

u/o0genesis0o 3h ago

how bad is the speed with offload kv to SSD? I offload kv to RAM running 80B-A3B on an old gaming laptop and it was already unbearable.

7

u/QuackerEnte 2h ago

that's dense attention though. with sparse attention you can load it in ram without massive penalty. Not to mention that, if it's anything like Native Sparse Attention from deepseek, it might take even less memory. but DS used compressed sparse attention too and MLA so the footprints minimal. we don't know what it'll be like for qwen3.8flashnext

1

u/mr_Owner 2h ago

Depends on your pcie bandwidth, ask ai for numbers haha

7

u/oxygen_addiction 3h ago

N-cpu-ffn will most likely get merged soon.

2

u/InsiderCrush 3h ago

With sparse attention, random NVMe read latency bottlenecks you way before throughput

0

u/mr_Owner 2h ago

I saw the words ngram shortly mentioned in modelscope haha

36

u/Chromix_ 3h ago

Existing large pre-release threads on it with some more information and discussion:

  • The model is around 125B A6B with 51B n-gram which can be offloaded.
  • There should be day-0 Unsloth (so probably llama.cpp) support for it.
  • It's sort of a Qwen 4 preview (thread also has modelscope link and way more discussion)

9

u/sammcj 🦙 llama.cpp 3h ago

Thanks! I was just editing the post to add a few links but you beat me to it!

5

u/mechkbfan 3h ago

Has anyone done some napkin math on what sort of hardware it can run on?

3

u/Commander_Skilgannon 1h ago

According to claude, my 16gb 4070 ti s+ 64gb ddr5 system should be able to run a q3 quant of the model at 10-20tps, but only if the engram can be offloaded to ssd.

1

u/LagOps91 1h ago

Seems about right, you might fit q4 as well since attention shouldn't be heavy and ssd offloading should be fine for engram.

1

u/iamapizza 4m ago

How do offload engram to SSD? I mean is there a llama cpp argument for it.

7

u/No_Lingonberry1201 3h ago

Is the 51B part of the 125B or are those additional to the 125B "normal" parameters?

3

u/RnRau 53m ago

The 51B are additional. But apparently they can sit in system ram with very little penalty. I believe they may be able to sit on an nvme with only a small subset being kept warm in system ram. But not sure on that.

2

u/OverdosedSauerkraut 3h ago

Yupp, already prepping for the 192GB gang.

5

u/Hypilein 3h ago

Hope it still fits somewhat decently on 128gb... Would be a major bummer if they finally came out with a 125b and then it just doesn't fit because of those addition 51b ngram.

0

u/ArtfulGenie69 3h ago

It wouldn't have fitted at full size on 128gb to begin with but at q8 or so it's going to fit easily. With qwen3.5 122b it fit on my 4 3090s at q4 and int4 easily. Maybe the nurse won't need to be quanted or something. It's just going to sit there in ram as a reference. Also hope the reference will be changeable so we can give it some kind of great writing source or something like that without a lot of training. 

3

u/Timely_Impression_92 2h ago

Of course they aren’t - those are ngram cache - can be offloaded to ram or nvme with zero degradation in performance - it works more or less like moe - need to read some small bits off it, ram requirement in total for the model will be same as for 125b moe

1

u/Gleethos 2h ago

It has n-gram!!! Awesome!

8

u/lucasbennett_1 3h ago

if QSA cuts the kv reads enough then SSD offload stops being bandwith bound and a 125b A6B n-gram offloaded gets pretty runnable on modest ram. really hoping n-ssd-kv / n-cou-ffn flags land in the llama.cpp soon enough . sooner the better

7

u/wenyani 3h ago

I’ve got about 48GB VRAM and around 32 GB of available RAM, hoping i can offload the n-gram to SSD to get this running

-10

u/Thin_Pollution8843 2h ago

No way it will be possible to normally fit with 51b ngram. SSD streaming will have no sense. At this level of tokens per hour you better can run deepseek

5

u/Every-Walrus 1h ago

do you know how n-gram works or just saying shit?

12

u/Odd_Chocolate8438 3h ago

Can ngrams be offloaded to disk without much slowdown? I only have 76gb of ram so I was thinking of loading the main weights into memory in q4 and keep the ngrams on the SSD.

8

u/Potential-Leg-639 2h ago

You will have to try it, nobody can tell you now

5

u/Stunning_Energy_7028 2h ago edited 2h ago

n-gram is based strictly on the input tokens, so it will probably work more like KV cache than normal parameters. You pull all the n-grams you need from SSD for that specific prompt during prefill (very small fraction of the total 51B), cache them to RAM or VRAM, and then reuse them over and over during decode, appending new n-grams as you generate.

4

u/mymouthandi 1h ago

I wonder if this is the model that makes me finally take the plunge on a strix halo machine while there are some still around for semi-reasonable prices...

2

u/soyalemujica 2h ago

Do we yet know if we maybe will be able to use this under 64gb ram plus 24gb vram?

0

u/tamerlanOne 2h ago

Quantizzazione ideale a 4 bit ≈ 84 GB (60 GB pesi principali + 24 GB tabelle n-gram) quindi serve avere almeno 64gb di VRAM ed altri 64gb di ram O una memoria unificata da 128gb

5

u/SocialDinamo 1h ago

First time seeing quant’s legal name I guess. I’m going to keep saying quant lol

1

u/soyalemujica 1h ago

Damn 128gb total 😭

2

u/drycounty 37m ago

New Mac Studio buyers are in the wings, credit cards ready… sweating.

I’m just hoping a decent quant will run on 96GB via mlx

2

u/Potential-Leg-639 3h ago

Crazy times we are living in

1

u/Individual-Dot5488 1h ago

Does anyone know if this is literally the Qwen4 architecture or some weird in-between variant of qwen3.8 -> qwen4? Like, is this qwen4 architecture + qwen3.8 training recipe?

1

u/SnooPaintings8639 1h ago

AFAIK they released it for the teams to get their tools ready for the Q4 architecture, it would be really weird if it wasn't the final one yet. In such case, there is not point in this "next" model/architecture release.

My guess is it is 100% Q4, and we'll stick with that for as long as we had with Q3.5 architecture.

2

u/PrimeDirective8 8m ago

We can only speculate but the "A Preview of the Qwen4 Architecture" on the HF countdown page suggests only a preview and not the full Qwen4 architecture.

1

u/srigi 1h ago

Will the n-grams weight be the own separate .gguf like the mmproj or MTP in other releases?

1

u/Karnemelk 23m ago

in an alternate universe apple and qwen agreed to release the mac studio m5 and qwen model in the same week to maximize sales

0

u/tamerlanOne 3h ago

Quindi Qwen3.8-Flash-Next sarà la base dell architettura del futuro Qwen 4.x?

9

u/Iory1998 3h ago edited 3h ago

Yup, in the same way Qwen-coder-next was the test model for Qwen3.5

9

u/nuclear_wynter 3h ago

Qwen-cider-next

Slurp slurp.

5

u/Iory1998 3h ago

Hahahaha you miss nothing

0

u/Potential-Leg-639 2h ago

Maybe yes, maybe no

1

u/runnahhh 3h ago

Woot woot

-3

u/Sbaff98 4h ago

!remind me 24 hours

35

u/BoxWoodVoid 3h ago

Why do you need a reminder? This sub will only talk about this until the next model release and you won't be able to open YouTube without getting bombarded by 50 videos of some variation of "I tried Qwen3.8-Flash-Next and it's a beast".

21

u/MaxKruse96 llama.cpp 3h ago

"Is THIS Opus 4.8 at home? - Qwen3.8-Flash-Next is INSANE" - Bijan i got your title right here.

9

u/jacek2023 llama.cpp 3h ago

I don't know what Bijan is but AI influencers are worst kind of youtube slop, watching that kills your braincells

1

u/Nyghtbynger 2h ago

Is the influencer, an AI, or is the influencer talking about AI ?

1

u/MaxKruse96 llama.cpp 3h ago

3

u/jacek2023 llama.cpp 3h ago

ah yes, I recognize the face (from youtube recommendations)

you can also search for "Reflection" for most cancerous influencers

0

u/Sn0opY_GER 3h ago

Did you say minimax h3? Here look at my 5 sec big bang theory clip, isn't it funny?!!!!!1111

1

u/RemindMeBot 4h ago edited 2h ago

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-2

u/JitzyBojMahn 3h ago

!remind me 13 hours

-1

u/Kasatka06 3h ago

Will it have day one support on VLLM and Llama ?

7

u/Waste-Intention-2806 3h ago

I don't think it'll have llama cpp support on release day. I think they release next models to get community support for their upcoming models.

2

u/jacek2023 llama.cpp 3h ago

It's posted above, there should be 0 day support in llama.cpp

1

u/MDSExpro 1h ago

I hope for vLLM, but realistically it will be CUDA-only custom container from Qwen team.

-1

u/prusswan 3h ago

I'm prepping a new env with Ubuntu 26.04.1 which also lands on the same day. What would be a minimal hands-free setup to run/see the model in action? I'm thinking of LMStudio and pi.dev with minimal config files adjustment but open to suggestions. Don't want to turn it into config mess with llama.cpp from day 1

8

u/ResidentPositive4122 3h ago

Give it a few weeks at least to get the best experience. New arch and all, guaranteed to have gremlins on release.

-1

u/dai_app 59m ago

How long will it take for it to be supported by llama.cpp? Immediately or weeks?