I can't get 3.8 to exit thinking loops. It will just think and think and think on the most trivial topics. I wanted it to port a speed test powershell script to c#. Claude opus 5 completes it under 60 seconds. I let 3.8 churn about 6 different times for 30+ minutes and it never wrote a single line of code to disk. It wrote lots of lines in thinking.

unsloth/Qwen3.8-27B-GGUF UD-Q3_K_XL DSH (pi)

Any tips?

I've found it tends toward long thinking loops even for simple tasks (and any quantization seems to increase their length), but those do exit eventually, unlike with Qwen 3.6.

I use the Unsloth UD_Q2_K_XL GGUF with default parameters, along with that custom template linked elsewhere in the thread, and no K/V cache quantization.

My experience has been that anything less than a 4-bit quant has a tendency to go off the rails. There’s a threshold of coherency that is being crossed somewhere internal to the model I guess.

Try the same prompt with a larger quant (even if it runs very slowly because the model no longer fits in VRAM) & see if Qwen does better - if so, there’s your answer.

That sounds like something is off - I'm using UD-Q4_K_XL on pi with xhigh thinking, and unless I'm vastly underestimating the complexity of the script that's the kind of task I would expect to take a couple of minutes (getting ~30t/s decode). What server are you running, and are you using the recommended parameters from qwen/unsloth?

set thinking to minimal and use these jinja templates: https://huggingface.co/froggeric/Qwen-Fixed-Chat-Templates

we went from 62% completion to 92% using a claude code harness

Use Muse Glimmer. It’s good.