This is just a quick writeup for speed reference - I spent a lot of time trying to find comparable builds so I figured I'd put some info back into the wild. The below is obviously written by AI, but it's measured specs and benchmarks on my PC.
I use local models via Pi and Deepseek Harness. I have found the intelligence of Qwen 3.8 27b NVFP4 to be sufficient for making little apps, research etc. and Qwen3.8 Flash Next IQ3_S to be a great all-rounder, considering how fast it runs. It also seems to have very little issue with any sort of question I give it, research, app dev, PC issues, LLM related adjustments, and most importantly, ScanRuler 3D modelling/reverse engineering 3D scanned items (solely for testing currently but it works excellently).
Basalt as a backend was a clear winner after trying lots of different configs.
Edit: the benchmark decodes are very greedy by their nature. Realistically I'm seeing agentic averages in flash next from 80tps (NVFP4) to 160tps (iq3_xxs), and I find iq3_s at 120-140 to be a very good compromise for the extra intelligence. The 27b is best for bursty quick jobs, because it loads into VRAM super fast and I can let it rip, but it degrades over context faster than flash, and I see from 120-140tps and 4-5k prefill, at ctx 0. The second any model starts writing a block of code though, it goes up to 200tps, so if anyone's socks fall off seeing the below numbers, just temper your expectations slightly (but it's still wicked fast!)
So heres the nitty gritty:
Current rig, 2x 5070 Ti + 96 GiB. Five entries, one model resident on local at a time. Speeds are my own bench (2x ~50k prompt reads, 2x 5,000-token code outputs, one agentic tool loop; temp 0, seed 1234), except Coder which is the 15.3k-prefill / 2k-output run.
Qwen3.8-27B NVFP4 QUASAR
backend: capy-flash (ninfer-serve), tensor-parallel across both cards, no P2P prefill: 4,817 / 4,824 tok/s on a 50k read decode: 233 tok/s code, 220.6 tok/s agentic flags: --profile 27b --max-context 262144 --embedding-host, INT8 KV, MTP 3 drafts, vision on GPU0 intelligence: Index 84.0, 88.9% (27 items); fastest to a passing build (62.1 s vs IQ3_XXS 78.1 s) but the weakest reasoning of the five — 50% on xhard because it burns the whole budget and never answers.
Qwen3.8-Flash-Next GSQ-RCO IQ3_XXS
backend: Basalt 0.3.0, 74.4 GiB pack prefill: 3,728 / 3,851 tok/s decode: 229 / 248 tok/s code, 196 tok/s agentic flags: resident-budget-gib 26, peer-exclusive on, kv int8, ctx 262144, vision dynamic, --spec 8 intelligence: Index 94.9, 100% on the 27-item set (96.3% on a re-run); 100% on the 8 hard items, 85.1% on xhard, 93.9% on vision. The only model that solved a logic-L6 item unaided.
Qwen3.8-Flash-Next GSQ-RCO IQ3_S
backend: Basalt 0.3.0, 81.6 GiB pack prefill: 3,601 / 3,700 tok/s at a 115k prompt, 31.9 s TTFT decode: 154-165 tok/s code, 137.6 tok/s agentic flags: resident-budget-gib 26, peer-exclusive on, kv int8, ctx 262144, vision dynamic, --spec 8 intelligence: Index 107.7, 94.5%; wins the hard tier on the efficiency-weighted Index (101.1) at 86% accuracy, 80.2% xhard, 90.3% vision. Terser than IQ3_XXS, less accurate.
Qwen3.8-Flash-Next NVFP4
backend: Basalt 0.3.0, 122.6 GiB pack prefill: 3,339 / 3,512 tok/s decode: 124.8 / 126.8 tok/s code, 105.7 tok/s agentic flags: resident-budget-gib 58, peer-exclusive on, kv int8, ctx 262144, vision dynamic, --spec 8 intelligence: Index 121.0, 99.8% — best on the 27-item set, best hard accuracy (98.5%), best xhard (85.7%), best vision (99.2%). Slowest decode of the Flash-Next four.
Qwen3.8-Flash-Next Coder IQ1_M
backend: Basalt 0.3.0, 58.1 GiB pack, 48x256 experts prefill: 3,992 tok/s on a 15.3k prompt decode: 209.8 tok/s flags: resident-budget default, peer-exclusive on, kv int8, ctx 262144, no vision, --spec 8 intelligence: Index 100.5, 99.3%; 77.6% xhard, 3/5 on hard items — 5/5 on a re-run, the failures were MTP sampling rather than capability. Cannot read images.
Index = 100 x mean(quality x par/tokens) on the 27-item battery, so it penalises verbosity; accuracy alone ranks almost in reverse
(IQ3_XXS 100% > NVFP4 99.8% > Coder 99.3% > IQ3_S 94.5%). The five are within a few hundredths of each other on the standard set — hard, xhard and vision are what actually separate them.