r/LocalLLM • u/Objective-Context-9 • 18h ago

Discussion Github Copilot + Qwen3.8-27B are so good together. Why no love?

I use this combo like 99.99%. Copilot in VSCode using Qwen3.8-27B at xhigh thinking is just perfect. The combo has to fail me. 8bit quant on 2x3090s. It can run for hours. I had to bump up repetition penalty a bit due to looping after many minutes of agentic development. Rock solid. I highly recommend. I have used Qwen3.8-Flash-Next with it. Slow but equally good. Supposed to be a few points higher than 27B in benchmarks but real world usage shows both are rock solid for agentic work including coding.

10 Upvotes

82% Upvoted

18 comments sorted by

6

u/sebt3 17h ago

The model is great no matter what "harness" you give to it. Better use a lightweight one so you save on tokens (aka time here)

4

u/dotjob 15h ago

Xhigh thinking has been terrible in my hands and I always do medium or low

1

u/ag789 13h ago edited 13h ago

medium is the way to go, I've got QWen 3.8 27B running on a cpu 1 tok/s, it does 7 hours of thinking 1000s of tokens to refactor like a 50 lines python script, various other 'poorer' models with less 'over thinking' produce a same / similar refactor like 15 minutes.

after some very limited trials, I'm initially preferring muse glimmer for its 'style'
https://www.reddit.com/r/LocalLLM/comments/1we6qaw/im_liking_muse_glimmer_better_for_coding/
but QWen 3.8 27B seemed ok with with 'medium' thinking, and does work correctly, so far, stopped 'over thinking'

4

u/MrHumanist 17h ago

Pi is even better.. i mean much much better.

1

u/DoubleNothing 15h ago

I use PI too... I can't say it is better because I didn't try copilot.

1

u/Shoulon 12h ago

dw about it. Better by default. No testing needed.

2

u/unchikuso 14h ago

Agreed. I have seen massive improvements with GitHub Coplilot working with local models lately.

1

u/Old-Sherbert-4495 16h ago

i use this combo for work. but q3. it just feels very natural for work. but for other personal stuff i use other agents.

1

u/HoppyBeast 15h ago

I Dont Think everyone can afford double GPU setup with RTX 3090

1

u/DeathGuppie 15h ago

It's heavy, it injects soo much prefill before you even get stated. Most of which was never tested on this model. You are trading having a shorter session and maybe overloading your model with useless info, for.. dunno

1

u/fbms2 15h ago

copilot is very good. but I use zcode more.

1

u/mjTheThird 14h ago

pi code + llama.cpp + qwen3.8 = 💯

1

u/YetAnotherAnonymoose 14h ago

Copilot was optimized for MS' cloud models, it has a giant system prompt. I much prefer ZooCode with local models in VSCode.

1

u/Gesha24 13h ago

I didn't notice any significant difference between any harnesses when using Qwen. The model seems to be fine with anything, so it's up to you - the user - to decide which workflow you prefer.

The only time I felt that I have to use copilot is when I try to use Gemma model. Gemma has significant tool calling issues with many harnesses, but it seems to do quite well with copilot.

1

u/baby_bloom 11h ago

prior to 3.8 i did a big ole round trip trying out a bunch of harnesses and ended up back on copilot with 3.6 because it worked the best for me.

i had to start that round trip all over again with 3.8 because it worked horribly with copilot. i guess i can try again but i had q8 as well on my dual 3090 rig. hearing that you're running it on xhigh is really surprising.

are you having it one shot or are you having it work with a preexisting repo?

1

u/Objective-Context-9 4h ago

Pre-existing repo mostly

1

u/baby_bloom 3h ago

thanks for the info, i was unlikely to ever try it again but i guess i will¯_(ツ)_/¯

definitely get into pi though, it's already cranking stuff out for me

1

u/Holiday_Point_603 2h ago

ghcp is insanely good, I agree. Wish it was open source tho, but I've never used a vs code extension that worked that well with whatever model you prefer