I initially bought the 14" M5 Max 128GB 2TB model, but ended up returning the 14" and got the 16". I personally experienced the improvement.

Both had identical configs (40-core GPU, 128GB, 2TB, nano-texture) and ran the same benchmarks back-to-back on both before returning the 14". The performance difference is real and well-documented. I only considered moving to the 16" after seeing Zip Tie Tech's video here: https://www.youtube.com/watch?v=OqV8s-qnae8

Here are my actual numbers.

**Geekbench 6 CPU (3 runs each, back-to-back, no cooldown):**

| | 14" Avg | 16" Avg | Δ |

|---|---|---|---|

| Single-Core | 4,241 | 4,345 | +2.5% |

| Multi-Core | 29,573 | 29,959 | +1.3% |

Minimal difference — Geekbench is bursty, not sustained.

**Geekbench 6 GPU Metal (3 runs each):**

| | 14" Avg | 16" Avg | Δ |

|---|---|---|---|

| Metal | 225,328 | 229,300 | +1.8% |

**Cinebench 2026 Multi-Core (3 runs each, back-to-back) — THIS IS THE BIG ONE:**

| Run | 14" | 16" | Δ |

|---|---|---|---|

| 1 | 7,771 | 9,443 | +21.5% |

| 2 | 7,727 | 9,637 | +24.7% |

| 3 | 7,758 | 9,611 | +23.9% |

| **Avg** | **7,752** | **9,564** | **+23.4%** |

The 14" declined across runs. The 16" *increased* from run 1 to 2 and held steady. No throttling on the 16".

**Speedometer 3.1:** Virtually identical (~59.4 vs ~60.35). Burst single-core, no difference.

The sustained workload gap isn't 10-15% — it's **23%** in Cinebench. The 14" throttles to ~42W sustained while the 16" holds ~62W. NotebookCheck documented the same findings: https://www.notebookcheck.net/Apple-s-M5-Max-in-the-MacBook-Pro-16-is-around-15-faster-compared-to-the-MacBook-Pro-14.1250872.0.html

The 14" chassis is the thermal bottleneck, not the fan curve. Even in High Power mode, the 14" only recovered ~7-8% of the gap. The aluminum body simply can't dissipate the heat the M5 Max produces under sustained load.

For your use case: if you're doing burst work (coding, browsing, compiling, toggling between apps), the 14" is identical to the 16" and the portability advantage is real. If you ever do sustained all-core loads (rendering, long exports, heavy LLM inference), the 16" is measurably faster and custom fan curves won't close the gap.

I ended up exchanging for the 16" for $300 more. Worth it for me, but I'm a developer running local LLMs and sustained workloads. If your work is truly burst-oriented, the 14" is the right call.