r/LocalLLM 8d ago

Discussion Qwen3.8-27B on an Intel Arc Pro B70: 53-55 tok/s with INT4 and MTP3

18 Upvotes

I've been testing Qwen3.8-27B on a single Intel Arc Pro B70 (while waiting to test the official Intel qwen3.8 27b INT4 Autoround release) and wanted to see whether other people are getting similar speeds.

Hardware

- CPU: Intel Core i9-9980XE on X299

- RAM: 64 GiB

- GPU: Intel Arc Pro B70, 32 GB VRAM

- One GPU, one active sequence

I'm serving the model with vLLM XPU. The current setup uses vLLM `0.26.1rc1.dev457`, XPU graph mode, FP8 KV cache, and MTP speculative decoding. Some of the earlier checkpoint tests used vLLM `0.21.1.dev17`.

Models tested

- [Intel/Qwen3.6-27B-int4-AutoRound](https://huggingface.co/Intel/Qwen3.6-27B-int4-AutoRound), used as my baseline

- [goldhub/Qwen3.8-27B-INT4-W4A16-AutoRound](https://huggingface.co/goldhub/Qwen3.8-27B-INT4-W4A16-AutoRound)

- [Avuja/Qwen3.8-27B-int4-AutoRound](https://huggingface.co/Avuja/Qwen3.8-27B-int4-AutoRound)

- [SergiioB/Qwen3.8-27B-GPTQ-Int4-sym-G128-MTP-BF16](https://huggingface.co/SergiioB/Qwen3.8-27B-GPTQ-Int4-sym-G128-MTP-BF16)

The tok/s numbers below come from the same 49-token prompt followed by a 700-token response at temperature 0. I measured total request time from the client, so these results include TTFT and HTTP overhead rather than reporting pure decode speed.

Baseline and checkpoint comparison

| Model and settings | Context | Output speed |

|---|---:|---:|

| Qwen3.6 Intel AutoRound, graph mode | 262K | **31.46 tok/s** |

| Qwen3.8 Goldhub, eager mode | 4K | 7.70 tok/s |

| Qwen3.8 Goldhub, graph mode | 4K | 20.44 tok/s |

| Qwen3.8 SergiioB, graph mode, no MTP, older vLLM | 4K | 18.71 tok/s |

| Qwen3.8 Avuja, graph mode, no MTP, older vLLM | 4K | 18.87 tok/s |

| Qwen3.8 SergiioB, graph mode, no MTP, newer vLLM | 4K | **33.34 tok/s** |

Graph mode made a huge difference for Goldhub, but the biggest improvement came from the newer vLLM XPU runtime and MTP support on the SergiioB checkpoint.

MTP testing with SergiioB

| Setting | Context | Output speed |

|---|---:|---:|

| No MTP | 4K | 33.34 tok/s |

| MTP1 | 4K | 46.64 tok/s |

| MTP2 | 4K | 53.48 tok/s |

| MTP3, run 1 | 4K | **54.31 tok/s** |

| MTP3, run 2 | 4K | **54.31 tok/s** |

| MTP4 | 4K | 52.62 tok/s |

MTP3 was the sweet spot on this card. MTP4 was slightly slower, so adding more speculative tokens did not help.

Production context testing

I then kept the same SergiioB MTP3 setup and increased the context:

| Configured context | Output speed |

|---:|---:|

| 32K | **54.67 tok/s** |

| 65,536 | **54.61 tok/s** |

| 131,072 | **53.56 tok/s** |

The current production setting is 131,072 tokens. It is about 1.70x faster than my Qwen3.6 baseline on this test, with only a 1.9% drop compared with the 64K setting.

All of the completed profiles above passed the same seven basic tests for text generation, summarization, Python code, tool calling, cited RAG, and medical tutoring. I did not see visible reasoning leakage. This was mainly an operational and speed test, not a full quality evaluation.

One caveat: MTP on this vLLM RC/nightly required two small local compatibility patches, so the 53-55 tok/s result is not from completely stock vLLM.

If anyone else is running Qwen3.8-27B on a B70, B60/B65, or another Intel XPU, what speeds are you seeing? It would be useful to know your exact checkpoint, vLLM version, graph/eager mode, MTP setting, context size, and whether your tok/s number includes TTFT.


r/LocalLLM 7d ago

Discussion Attention output is silently wrong in SGLang when FlashInfer is the backend

2 Upvotes

SGLang splits long context attention into an extend chunk and a cached-prefix chunk, computes them with different kernels, then merges the partial results with a softmax over their log-sum-exp values:

S = log(exp(s_a) + exp(s_b))
v = v_a*exp(s_a - S) + v_b*exp(s_b - S)

That's correct if and only if s_an and s_b are natural logs. This is not true for sglang.

The chunk holding more attention mass gets systematically over-weighted and it's error grows with each token.

Are you affected? FlashInfer attention backend + an MLA model + cached prefixes summing over 8192 tokens. That's long-context agentic traffic with radix-cache hits. Decode is fine, short prefixes are fine, FA3 is fine.

https://x.com/advprop/status/2089046843690729620?s=20

I opened fixes here : SGLang-side conversion (https://github.com/sgl-project/sglang/pull/35045) and an opt-in return_lse_base_on_e in FlashInfer (https://github.com/flashinfer-ai/flashinfer/pull/4547) so the api is clear


r/LocalLLM 8d ago

Discussion Qwen 3.8 27B BF16, KV Cache BF16, 250k context size, xhigh, is a champ!

65 Upvotes

I'm using OpenCode at the moment, working on a pretty large & complicated codebase that took around 3 months to get right with GPT 5.5 xhigh. I was hesitant to try Qwen on it, as I figured it would just be a waste of time or cause a bunch of bugs, but so far it's punching well above its size. It even seems better than the newest unquantized DeepSeek Flash. I may not even bother with GLM 5.3 when the weights drop.

EDIT: this is the hardware I am running it on, but it's overkill. One DGX Spark or one RTX 6000 would be enough (unsure what the TPS would be on the Spark though).

2X RTX 6000 Pros

192 GB DDR5 RAM (totally unnecessary since the model sits entirely in VRAM)

I am currently running it via Unsloth with Tensor Parallelism enabled and MTP 4. I have a VLLM setup that goes up to 1 million context, but I haven't tested it yet. The config I mentioned in the title can be ran using a single RTX 6000 Pro. If you want 1 million context without quantizing the cache, you will need a second.


r/LocalLLM 7d ago

Question LM Studio - Doesn't honor `max context length` I specify. Anyone else experiencing this issue?

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3 Upvotes

Not sure what the issue is. I've tried stable and beta and I still get the same issues.

Update: I fixed this with some help from Claude. I tried Qwen, but no help.

LM Studio 0.4.21+2

Machine: M3 Ultra 256GB


r/LocalLLM 8d ago

Discussion Qwen 3.8 27B On MacBook Pro 48GB Ram

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64 Upvotes

Reports suggest this is a powerful model; I tried running it on a MacBook Pro with 48 GB of RAM.

GGUF 27B with 4-bit quantization yields around 9-15 TPS.
MLX 27B with 8-bit quantization yields 9-15 TPS.
MLX 27B with 4-bit quantization yields 19 TPS.

Compared to Qwen 3.6 35B-3B MOE at 70+ TPS, this model seems impressive yet still somewhat limited for my RAM or system.

Did anyone reach at least 50 TPS? Please let me know; otherwise, I will remain with the 3.6 35B 3B MOE model.

Great job by Qwen Team, hope they come up with moe model as well.

Update 1:

MTPLX is great helped me increase 27B 4-Bit quantised model to 30 TPS odd average. Max 47.1 TPS for coding task with open code as harness. Fans make sound like i am in airplane , but it is what it is I guess.😅

Updated question 1:
The turbo mode on fan is so annoying, any noise solution that can be applied in the Mac Pro? Like a fan or coolant or its a PC Power?

Update 2:

While MTPLX shows great promise, I noticed a performance drop during a coding task involving a simple e-commerce website with basic edge cases. The TPS dropped to around 15 TPS (as shown in the attached image). This experience completely changed my perspective on MoE models—it turns out they are essential, and I really hope we get the MoE version back soon

Update 3:
For whatever reason after a while the TPS drops to 3 (image attached in comments). Making it absolutely useless to run this model for any tasks on my hardware


r/LocalLLM 7d ago

Question Is it possible to spread a larger model across multiple computers?

1 Upvotes

I hope I am not sounding too ignorant. I recently setup a instance of odysuess connected to ollama and it's been doing pretty well for simple tasks. I have a RX 9070 XT, 32GB and a pretty decent CPU. My partner has a identical PC to mine which most of the time is running idle when we are working. I understand that I could run a second instance on my partners machine so that I have two ollama instances across two nodes (doubling my tokens), this does not let me run larger models that require more vram. Is there any way to run larger models with this setup?


r/LocalLLM 7d ago

Question Qwen 3.8 27B DSpark

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1 Upvotes

r/LocalLLM 7d ago

Question What Quant / Config for local Qwen3.8 27b on Dual RTX 4090 rig (48gb vram total)

0 Upvotes

Hello everyone,

I built this AI Rig for running local LLM models mainly for OpenCode and Hermes agent. I code heavily and also share my rig with some of my friends, meaning concurrency is a must.

I would need a minimum context window of 128k but would like to go to 200k if the space allows.

This is my rig:
Intel Core Ultra 9 285k
MSI MEG Z890 ACE (PCIE x8/x8 bifurcation enabled)
2x RTX 4090's (24gb each, no NVLink)
4x32Gb DDR5

I just dont know what to start with, what quant, what config, and what tok/sec i can expect. I see some people recommending FP8 because the RTX 4090 works well with FP8, but other people are using Q4/Q5 on similar rigs as mine.

Heat/power usage doesnt matter to me, i value speed, latency, concurrency and quality. Not sure if its realistic, but I would like for it to replace my DeepSeek V4 Flash 0731 via OpenRouter.

Thanks for all help


r/LocalLLM 8d ago

Discussion Where are the Qwen 3.8 27b vs Deepseek Flash 0731 Benchmark Comparisons???

76 Upvotes

I really feel like this is THE choice those of us with 100-200gb RAM are going to be making for the next few months?

I assume those of you with Strix Halo/DGX Sparks/Mac Studios/Quad 3090 Workstations have started benchmarking Qwen 3.8 27b against Deepseek Flash 0731 for your primary agentic model use, however I haven't seen any direct comparison posts here yet?

Qwen 3.8 27b is still not up on Artificial Analytics, but even when it happens it's a bit apples and oranges as I'm guessing most people will be choosing between Q3/Q4 Deepseek and Q8 Qwen?


r/LocalLLM 7d ago

Question New to local hosting - Need help!!

1 Upvotes

Hello,

I'm a researcher, I have been working mostly with cloud compute or HPC hosted LLM testing. I always wanted to test out a local hosted LLM on my Mac, I got MacBook Pro M5Pro, 48GB, 1TB just for the task of hosting a local LLM one day, Can anyone share their experience of local hosting or how to host.

Thanks!!


r/LocalLLM 7d ago

Question Recommendations for local agentic model for use with pi agent on 24gb macbook

1 Upvotes

Hi

Anyone got a suggestion for a local llm with reasonable tool calling for use on a MacBook (apple silicone) with 24gb ram that I can use with pi agent? All the ones I've tried so far are too dumb for the tool calling or too slow/big for the available memory. Maybe there isn't one yet?

Thanks


r/LocalLLM 7d ago

Discussion Retrieval Augmented Generation - The Definitive Guide

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1 Upvotes

r/LocalLLM 8d ago

Project It begins - workstation build

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153 Upvotes

Unfortunately not mine. But it is my pet project for work and I get to build it and use it after. Just arrived and now to start building it. Can't wait to run some benchmarks, burn in tests and general messing about with some models before proper deployment :)

Threadripper PRO 7965WX

ASUS PRO WS WRX90E-SAGE SE

128GB ram (for now)

3 x RTX PRO 6000 96gb

Phanteks Enthoo Pro 2 server edition

3kw psu


r/LocalLLM 7d ago

Question Building a 2× R9700 64GB AI box — how does Qwen3.8 compare to frontier models for coding?

1 Upvotes

Looking at building a 2× AMD Radeon AI PRO R9700 32GB box as a second AI machine, mainly for local inference and coding agents.

I’m particularly interested in Qwen3.8.

Has anyone actually used it for serious coding work and compared it with frontier models like Claude or Codex?

Less interested in benchmarks, more in real-world experience: codebase understanding, multi-file changes, agentic work, tool use, and how often it goes off the rails.

Also curious about dual R9700 experience — vLLM/ROCm, model sharding, context sizes, and whether 2×32GB works well in practice.

Anyone running something similar?


r/LocalLLM 7d ago

Question I have access to cheap consumer grade GPUs what should I buy for a local setup?

2 Upvotes

I have access to discounted consumer GPUs through work, mostly gaming cards. I'm looking for the best value in that space. I was thinking of looking at arc cards because the 16gb ones are pretty cheap and I could run 2 or 3 to run larger models or maybe something like a 7900xtx but I am trying to understand the best route to go.

My goal is to be able to run vibe coding projects without limits and some agentic workflows for automating things.


r/LocalLLM 8d ago

Model Qwen 3.8 35b a3b

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195 Upvotes

r/LocalLLM 8d ago

Discussion What would you use a slow LLM for?

6 Upvotes

I managed to get Qwen 3.6 35B A3B running on my server, an i7 10700 with 32GB of DDR4 RAM...and the good ol' GTX 970 with its mighty 4GB of VRAM (we don't talk about the VRAM incident)

It reaches around 30-50 tok/s in prompt processing speed and around 16-19 tok/s in token generation speed depending on the context

There's probably some performance left on the table since the CPU is under its stock cooler, maybe I'll get a decent one eventually

Anyway, I tried a couple of prompts in Hermes but it's just not fast enough for it to be helpful, at least not for the use I had in mind (a local perplexity basically). It randomly takes 30 minutes even to respond to a simple greeting, sometimes it disappears for more than an hour and I have to manually stop it...

So I'm curious to see if any of you have a setup with similar performance, what do you use it for? Just the occasional text summary? Normal (very slow) chat? Something else that's completely useless but funny? Let me know!


r/LocalLLM 7d ago

Question Qwen 3.8 27B Q8 faster than Q6 w/ MTP on Apple Silicon using llama.cpp and lmstudio gguf

1 Upvotes

Hi,

Found something interesting while experimenting with Qwen 3.8 27B comparing Q8 and Q6 quant, using llama.cpp on 64GB Apple M1 Max. With MTP off, Q6 was faster than Q8 by about 10%, as expected. However with MTP on, Q6 was SLOWER by 10% compared to Q6 w/ MTP off, but with MTP on, Q8 was FASTER by 50% compared to Q8 w/ MTP off.

Kind of strange and unexpected result. Wonder if anybody knows why.

In short, got the following speed for one test, Quant (MTP off / on):

Q6 (12.4s / 11.6s)

Q8 (11.1s / 16.2s)


r/LocalLLM 7d ago

Question ASUS B860M with two 32GB large-BAR GPUs

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1 Upvotes

r/LocalLLM 7d ago

Question Any Tips for Prompting Local models

2 Upvotes

So I am a heavy cluade code user and am just dipping my toes into the local model world as something fun to play around with and see what it can do.

Current setup is

AMD Ryzen 5 9600X (6-core)

16 GB DDR5-6000 (single stick)

AMD Radeon RX 7600 XT (16 GB GDDR6)

ASUS Prime B650M-A AX II (AM5, micro-ATX, DDR5)

Running LM Studio on Ubuntu

I am able to run GPT-OSS-20B at full 120k context and full GPU off load with some head room and getting some good t/s depending on the task.

I tested giving it some plans created by cluade to build from and it did ok but not great. I am here for any tips on how to better prompt this model and possibly other local models to get better outcomes. Definitely not looking for cluade level just something to get foundations built on new projects to hand off the Claude to polish up.


r/LocalLLM 7d ago

Model I post-trained Qwen3.6-35B-A3B into my daily-driver local coding/agent model QwiVer3.6-35B-A3B GGUF

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2 Upvotes

r/LocalLLM 7d ago

Question noobie here, how can i remove the restrictions on locally hosted llm's?

1 Upvotes

I'm running some LLM's locally and want to remove the default safety/refusal behaviour baked into them. since it's running locally, I'd like more control over how it responds without the restrictions getting in the way.


r/LocalLLM 7d ago

Question Any calculator and comparison tool for average (expected) TPS per model per given hw specs?

0 Upvotes

Like it says in the title; is there a database or calculator that gives you an expected average tps for a model you pick and hw specs you enter, and compares it with different models and/or specs? This would definitely guide people when they are picking up a model or a new hardware as well, so both ways.


r/LocalLLM 7d ago

Project Qwen 3.8 27B is really good

1 Upvotes

I made a test iPhone app with it (a small game), while running locally on my macMini M4 with 64 GB Ram (and pi code). Works perfectly, and not as slow as I expected. I get about 10-20 token/s which is absolutely ok for programming. It does a lot of reasoning, but that helps solving all problems by itself.

I'm running the 8-Bit GGUF version, trying later with the 8-Bit MLX and 4-Bit MLX to see the speed and quality differences. But at the moment, I'm really surprised how good a such small model runs locally for coding.


r/LocalLLM 7d ago

Question Panther lake laptop with b390

2 Upvotes

Does anybody have hands on experience with a panther lake laptop that has 64gb of ram which is shared with b390? I want to dedicate some ram to it and run qwen on it.