The fastest way to run Qwen 3.8 on a Mac.
MTPLX is a native Mac app and a command line that runs local language models on Apple Silicon with the model's own multi-token prediction (MTP) heads. It runs Qwen 3.8 Flash Next, the 125B mixture of experts, Qwen 3.8 27B and Prism ML's Ternary Bonsai 2 27B, plus Qwen 3.6, Qwen 3.5 and Gemma 4. The model drafts several tokens ahead of itself, one batched forward pass verifies the draft, and tokens are committed through exact rejection sampling with residual correction. The sampler works at the model's native temperature, and decode runs at around twice the speed of plain decoding: measured 1.6x on a 16 GB M4 Mac mini and 2.24x on an M5 Max.
Measured speeds
Every number below was measured on a MacBook Pro M5 Max with 128 GB, fans verified at maximum, sampled at the model's own settings. Conditions and sources for every row, with the raw logs where they exist, are at mtplx.com/benchmarks.
| Model | Speed | Run |
|---|
| Qwen 3.8 Flash Next, Optimized Speed | 63.5 tok/s | 65,502-token prompt read at 1,094 tok/s (768 on 2.11.3), first token after 60.1 s instead of 85.5 s, 512 tokens generated, thinking off, MTPLX 2.12.0 (56.1 tok/s on 2.11.3) |
| Ternary Bonsai 2 27B, Optimized Speed | 64.4 tok/s | 4,061-token prompt, 512 tokens generated, MTP depth 1, thinking off, MTPLX 2.12.0 (52.6 for the 4-bit Qwen 3.8 27B in the same session), 11.4 GB peak |
| Qwen 3.8 Flash Next, Optimized Speed | 125.8 tok/s | one OpenCode request: 1,301 tokens generated, 18,539-token prompt with 18,364 tokens served from cache, MTP depth 3, MTPLX 2.11.3, 16 September 2026 |
| Qwen 3.8 Flash Next | 79.3 tok/s | 9k-token code prompt, 1,500 tokens generated, thinking off, two alternating boots each, MTPLX 2.11.3 (62.5 on 2.11.2) |
| Qwen 3.8 Flash Next | 61.8 tok/s | 109k-token OpenCode turn, mean of two runs, MTPLX 2.11.3 |
| Qwen 3.8 Flash Next | 50.3 tok/s | 200k-token OpenCode turn, warm, mean of two runs, MTPLX 2.11.3 |
| Qwen 3.8 27B, Optimized Speed | 87.6 tok/s | rewriting a file it just wrote, stock settings, MTPLX 2.10.0 |
| Qwen 3.8 27B, Bare Speed | 65.2 tok/s | fresh coding task at official Qwen 3.8 sampling, generation to the model's own stop, MTPLX 2.7.0 |
| Qwen 3.6 27B, Optimized Speed | 81.74 tok/s | the 27B record on a fresh generation: 192-token bench, thinking off, temperature 0.6, twin runs, 2.69x over 30.37 plain decode, 2 July 2026, raw logs |
| Qwen 3.5 4B, Optimized Speed | 227.8 tok/s | depth 3, 1.71x over 133.6 plain decode, MTPLX 2.2.0 |
MTPLX uses rejection sampling with residual correction at the model's native temperature. For 2.11.3, MTPLX compared a thousand four-token samples from the fast path with a thousand from the plain path at temperature 1, top-p 0.95 and top-k 20, by token id. Those measurements matched within the plain path's own noise on both Flash Next and the 27B Quality pack. From 2.12.0, image requests also use the compiled verifier, and that sampled comparison has not yet been repeated for images. The acceptance rule follows the Leviathan and Chen rejection sampling theorem; numerical equivalence of the model's execution paths is checked separately. There is no second draft model eating your RAM, and no greedy shortcut that quietly changes what the model would have said.
How MTPLX compares with mlx-serve, oMLX, LM Studio, Ollama, llama.cpp and mlx-lm, with a version, a machine and a date on every number: mtplx.com/compare.
Get it
The Mac app is the easiest way in. Download the DMG at mtplx.com, drag it to Applications, and the app takes care of everything else: it checks your hardware, recommends a model that actually fits your memory, downloads it, sets up its own Python engine (no Homebrew needed), installs fan control, puts mtplx on your PATH, and then measures your machine to pick the fastest decoding depth.
Recommended for coding: Qwen 3.8 27B Optimized Speed is a 4-bit dynamic
quant with great coding speeds and good quality. Its two siblings sit right
under it in the app and CLI: Bare Speed (quickest burst chat speeds, lower
quality and slower on long coding tasks) and Optimized Quality (8-bit dynamic
quant, the highest fidelity of the three). Qwen 3.8 Flash Next is offered as
Bare Speed from 96 GB and as Optimized Speed from 128 GB, and on a Mac with
256 GB or more Flash Next Optimized Speed is the first recommendation. Qwen 3.6
Optimized Speed V2 remains available below them.
The CLI on its own:
brew install youssofal/mtplx/mtplx
mtplx start
or python3 -m pip install mtplx if you prefer pip. All releases are listed at mtplx.com/releases.
Requirements: Apple Silicon (M1 or newer), macOS 14+. The app and CLI use
one recommendation policy on M3, M4 and M5: Qwen 3.5 4B Optimized Speed below
16 GB, Ternary Bonsai 2 27B from 16 GB, Qwen 3.8 27B Optimized Speed from
32 GB, and Qwen 3.8 Flash Next Optimized Speed from 256 GB, with Flash Next
Optimized Quality second. M1 and M2 keep their FP16 recommendations.
Installed models and explicit selections remain available.
Ternary Bonsai 2 27B and Flash Next Optimized Quality require MTPLX 2.12.0 or
later.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
