Benchmark / AI PCs & local LLMs

AI PC benchmark: local-LLM speed and memory (2026)

Token speed ≈ memory bandwidth ÷ model size; unified-memory capacity decides which models fit; NPU TOPS is largely marketing. Here is the comparison that actually predicts local-LLM performance — with sources and honest caveats.

By Evan Cole · Last updated July 17, 2026

Local-LLM speed is easy to predict once you know the one rule the spec sheets bury: token-generation speed is roughly memory bandwidth divided by the size of the model in memory (real output lands around 50–80% of that ceiling). Unified-memory capacity decides which models you can load at all; bandwidth decides how fast they run. The NPU “TOPS” number the boxes advertise is close to irrelevant for large-model text generation — mainstream runtimes (llama.cpp, Ollama, MLX) use the GPU, not the NPU, and decode is bandwidth-bound, not arithmetic-bound.

So this table leads with memory and bandwidth. The tokens-per-second column is drawn from independent testers using different models, quantisations and frameworks — treat it as directional, not a single controlled benchmark. Figures are aggregated from independent inference testing, cited by source.

Local-LLM comparison table

Machine Silicon Unified mem (GB) Bandwidth (GB/s) NPU TOPS Max model @ Q4 Measured tok/s (independent)
Apple Mac Studio (M3 Ultra) Apple M3 Ultra 256 819 32-core NE ~405B Q4 (up to 512 GB config) ~16.5 tok/s (70B, MLX)
Apple Mac Studio (M4 Max) Apple M4 Max 128 546 38 70B dense / ~100B MoE Q4 ~60 tok/s (120B MoE); ~7 tok/s (70B)
Apple Mac mini (M4 Pro) Apple M4 Pro 48 273 38 70B Q4 tight (32B comfortable) ~11 tok/s (34B)
ASUS Ascent GX10 NVIDIA GB10 128 273 GPU ~1 PFLOP FP4 ~200B MoE / 70B dense Q4 ~2.7 tok/s (70B); 11.7 (120B MoE)
Beelink GTR9 Pro Ryzen AI Max+ 395 128 256 50 ~120B MoE / 70B dense Q4 ~5 tok/s (70B); 72 (30B MoE)
Minisforum MS-S1 Max Ryzen AI Max+ 395 64 256 50 70B Q4 ~5 tok/s (70B)
Apple Mac mini (M4) Apple M4 24 120 38 ~14B (7–8B comfortable) 42 tok/s (8B)

Sorted fastest-bandwidth first. Prices and Amazon sellers on these niche machines are volatile and often reseller-inflated — re-check before buying. Full picks, verdicts and pros/cons are in our best AI PC for local LLMs guide.

How to read this

Bandwidth is the speedometer. On a Llama-3 70B dense model, the ~256–273 GB/s machines (NVIDIA GB10, Ryzen AI Max, Mac mini M4 Pro) cluster around 3–5 tokens/second; the Mac Studio M4 Max at 546 GB/s is markedly faster; and only the Apple-direct M3 Ultra at 819 GB/s reaches the ~16–20+ tok/s range. If you want responsiveness on big models, bandwidth is what you're buying.

Unified memory is the door. It decides which models load at all. As rough footprints: Q4 ≈ 0.55–0.6 GB per billion parameters, Q8 ≈ 1.1 GB per billion, then add 10–20% for context/KV-cache:

  • 24 GB → 7B–14B comfortably; not 70B.
  • 48 GB → 32B comfortably; 70B Q4 tight.
  • 64 GB → 70B Q4 comfortably.
  • 128 GB → 70B at Q8, or a ~120B mixture-of-experts model at Q4 (but a 235B MoE ≈ 132 GB still won't fit).
  • 256 GB → ~405B at Q4 tight (M3 Ultra territory).

Ignore the TOPS race. “50 TOPS,” “48 TOPS,” or platform totals over 100 TOPS describe the NPU, which helps with lightweight on-device features — not with how fast a 70B model answers. Judge a local-AI machine on the two columns above, not the marketing number.

Sources & method

Memory and bandwidth figures are from manufacturer specifications (NVIDIA DGX Spark documentation for GB10; Apple's Mac Studio and Mac mini spec pages; Framework, Corsair and HP spec pages for Ryzen AI Max). Tokens-per-second figures are independent third-party measurements (ServeTheHome, Level1Techs, LMSYS, MLX community results and MacRumors), gathered under differing quants and frameworks — presented as ranges, not one apples-to-apples chart. This page was produced with AI assistance as part of VerdictBits's research workflow; every spec was cross-checked against a primary source before publication, and figures we could not independently verify are flagged in the guide.

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