On-device LLM benchmark for Apple Silicon — iPhone · iPad · Mac.
A neutral, reproducible benchmark for running local LLMs (and, in time, ASR / TTS) on Apple Silicon. Compares MLX Swift, llama.cpp, CoreML (swift-transformers), LiteRT-LM, ExecuTorch, ANEMLL, Apple Core AI — and Apple's own Foundation Models — under real device constraints, not just tok/s on a server.
Repo:
apple-silicon-llm-bench· CLI/brand:yardstick. Started life asios-llm-benchmark— iPhone is still the headline target, now measured alongside iPad and Mac.
Core AI is Apple's Core ML successor, announced at WWDC 2026 (iOS / macOS 27). First independent on-device LLM benchmark — vs MLX and CoreML, same model, same harness.
iPhone 17 Pro · Qwen3-0.6B · short-chat · decode tok/s (cold = fresh-process first generation; warm = in-process median of runs 2-4, fairness-rules §2):
| Engine | Compute | Cold | Warm (r2-4) | Peak RAM | Session |
|---|---|---|---|---|---|
| Core AI (pipelined) | GPU | 193.3 🏆 (first-ever 76.5) | blocked† | 196 MB | 2026-06-18 |
| MLX | GPU | 167.2 | 158.8 | 489 MB | 2026-07-13 |
| Core AI (static-shape) | ANE | 143.7 | blocked† | 1,158 MB | 2026-06-18 |
| LiteRT-LM | GPU | 121.0 | 120.4 | 1,384 MB | 2026-07-13 |
| CoreML-LLM | ANE | 39 | pending‡ | 184 🏆 | 2026-06 |
Read the Session column before comparing rows. Cross-session ratios are invalid on this device: the same MLX binary + pins measured 126–133 tok/s in mid-June and 159–180 today (device-state change, likely an iOS 27 beta update — full investigation with raw data:
results/raw/2026-07-13-mlx-variance/). Within-June sessions Core AI GPU led MLX (193.3 vs 126–133 cold ≈ 1.5×); today's same-session Release warm gives LiteRT-LM ≈ 0.76× MLX. This replaces the earlier Debug-contaminated MLX 112 row and the "~1.6× once warm" framing.† Core AI warm re-capture is blocked:
coreai-buildaborts on the current macOS 27 beta (both toolchain generations) so the 0.6B bundles can't be re-assembled —methodology/coreai-build-regression-2026-07.md. Core AI cold/warm behaviour is instead re-verified at 4B (bundles survive on-device). ‡ CoreML-LLM stateful-chunks bundle needs re-conversion before it can be re-measured.
- Core AI's GPU "pipelined" engine was the fastest path in the June session — cold 193.3 after a one-time first-ever cost (76.5 on the very first generation while the shader/pipeline caches build; subsequent fresh processes hit ~194). MLX and LiteRT are flat cold-to-warm.
- Core AI's compute unit is fixed by the export shape, not a runtime flag:
coreai.llm.export … --platform iOS(static) is detected as chunked-static → the ANE; a dynamic export → the GPU pipelined engine. And iOS can't JIT the exported IR — it must becoreai-build compile-d to a per-GPU-arch.aimodelcfirst (No such file or directoryotherwise). - CoreML-LLM is the memory champion — 184 MB, ~6× leaner than Core AI's ANE path — via a stateful INT4 Neural-Engine conversion (own work, 100% ANE residency).
- Faithful to Apple's intended path: official
coreai.llm.export+ thecoreai-modelsCoreAILMruntime, driven by the in-treeCoreAIRuntime. Method + gotchas:methodology/coreai-ios.md.
Does the GPU lead hold at scale? (Mac M4 Max, same params)
| Model (4-bit) | Core AI GPU | MLX | Core AI lead |
|---|---|---|---|
| Qwen3-0.6B (macOS-26 export) | 1,121 | 455 | 2.47× |
| Qwen3-0.6B (macOS-27β re-export) | ~500 | 455 | 1.1× |
| Qwen3-8B | 94 | 90 | 1.05× |
Core AI's pipelined-GPU lead is large on tiny models — where its async-dispatch / overlap dominates — but converges to a near-tie at a realistic 8B, where both runtimes become memory-bandwidth-bound. (Matched: 512-token prompt, 512 gen, greedy, warm. Core AI via Apple's llm-benchmark; MLX via mlx_lm.)
⚠️ The 0.6B number is export-generation-dependent. The samecoreai.llm.exportrecipe produces a 2.2× slower artifact after the macOS 27 beta upgrade (native quantized-Linear lowering → explicit dequant ops; same runtime, same code, same wheels). Forensics:methodology/coreai-export-lowering.md. Benchmark the artifact you ship.Confirmed on iPhone 17 Pro (both artifacts AOT-compiled
--architecture h18p, GPU, synthetic 512p/1024g — deeper-KV protocol, NOT comparable to the short-chat table above): macOS-26 artifact 115.1 tok/s decode / 5,807 prefill / 0.22 GB footprint vs 27β artifact 57.2 / 1,519 / 0.47 GB — ~2× decode, 3.8× prefill, half the memory, from the export environment alone. ANE (official iOS static preset, same protocol): 69.6 tok/s, 0.045 s warm load.
Full official-recipe matrix (M4 Max, macOS 27β artifacts, llm-benchmark defaults 512p/1024g/5):
| Model | Artifact | Core AI decode (prefill) | MLX 0.31.3 decode (prefill) | Decode verdict |
|---|---|---|---|---|
| gpt-oss-20b (MoE, MXFP4) | 13 GB | 78.1 (1,252) | 100.2 (1,528) | MLX +28% |
| qwen3-0.6b | 335 MB | 484 (9,396) | 432 (9,366) | Core AI +12% |
| qwen3-4b | 2.1 GB | 145.4 (1,635) | 145.8 (1,495) | tie |
| qwen3-8b | 4.3 GB | 94.1 (912) | 90.0 (825) | Core AI +5% |
| gemma3-4b-it | 2.1 GB | 141.5 (1,669) | 136.3 (1,631) | Core AI +4% |
| gemma3-12b-it | 6.2 GB | 55.0 (578) | 55.1 (528) | tie |
| mistral-7b-v0.3 | 3.8 GB | 101.7 (976) | 97.5 (918) | Core AI +4% |
Core AI matches or beats MLX on every dense model; MLX's one clear win is the MoE
(expert dispatch, not the core engine). On noise: per-trial σ is ≤0.4% on 6 of 7
models (worst 1.3%) — the dense deltas are 10–30× trial noise with a consistent
direction; cross-machine variance is what independent reproduction tests (welcome —
per-trial JSONs + env pins in results/raw/). gpt-oss-20b bonus: COREAI_CHUNK_THRESHOLD is a
memory dial — unchunked 4096-token prefill hits 1,439 tok/s (+16%) at 18 GB dirty
footprint, chunk-128 (the llm-runner MoE hint) caps memory at 1.7 GB for 766 tok/s.
Raw logs + env pins: results/raw/2026-06-11-m4max-coreai-matrix/.
Every bundle measured here is downloadable (hashes + env stamps on the cards, incl.
the irreproducible macOS-26 0.6B artifact): HF <model>-CoreAI-official repos.
Real LLM inference on a phone — on-device, no server. iPhone 17 Pro, short-chat (128 tokens), thermal-nominal. The winning runtime depends on what you optimize for — speed, memory, or quality. Gemma rows are the 2026-07-28/30 fairness re-capture (warm protocol: runs 2–3 median of n≥6 launches, run 1 dropped as cold, ctx forced 2048); per-cell dates and n are stated in the table.
2026-07-28/30 fairness re-capture. Every Gemma comparison below is now like-for-like: one warm protocol, one prefill instrument for every arm (a harness bug had discarded LiteRT-LM's task-path prefill counters on capped runs — fixed in the r3 harness and proven on device), both MLX rows in one session, and memory on the median charged footprint. Full records with per-cell n and number-trace audits:
results/raw/2026-07-29-gemma4-e2b-protocol/(iPhone) andresults/raw/2026-07-28-gemma4-e2b-protocol-mac/(Mac). Energy re-published on a rebuilt instrument: the old J/token figures are retired — iOS 27's battery gauge reports in 5% steps and start/end deltas swing ×2 between identical runs (evidence). The ◊ column now measures between gauge transitions (tick-window, audited); on it LiteRT leads iPhone energy (LiteRT 0.147 vs MLX 0.182) while the Mac's GPU-only powermetrics basis has MLX first — the energy verdict genuinely differs by OS.
The earlier version of this table had each arm on a different checkpoint quality class (MLX and llama.cpp on PTQ, LiteRT on QAT) — it measured who had the better checkpoint, not the better runtime. This one states the build per row, the capture session per cell, and adds GSM8K n=100 (measured on M4 Max with one identical harness for every row — greedy, thinking-off, same extractor). Decode/ITL are the warm protocol; memory is the median charged footprint over the same warm session:
| Runtime | Build | Decode tok/s | ITL p50 | Mem MB (median fp) | GSM8K | J/tok ◊ |
|---|---|---|---|---|---|---|
| 🔴 LiteRT-LM | wNa8o8 QAT (official) | 61.1 🏆 (A2 7/28, n=8) | 16.3 ms | 497 🏆 | 86.0% | 0.147 🏆 ◊ |
| 🌵 Cactus ¶ | CQ4 uncalibrated (their pre-07-09 build) | 50.6 (7/20 cold ×3 — warm not re-measured) | 19.6 ms (7/20) | 1,061 (7/20, peak basis) | 87.0% | 0.222 ◊ |
| 🌵 Cactus | CQ4 as shipped (cactus run default) |
50.0 (C 7/29, n=8) | 19.8 ms | 632 | 3.0% | 0.226 ◊ |
| 🟣 MLX-Swift | PTQ 4-bit | 49.1 (A2 7/28, n=6) | 20.5 ms | 3,010 | 84.0% | 0.182 ◊ |
| 🍎 Core AI ‡ | own int4 (from official QAT q4_0) | 47.1 (C 7/29, n=8) | 21.4 ms | 755 † | 88.0% | — (structural ◊) |
| 🔵 llama.cpp | Q4_K_M (PTQ) | 38.8 (7/27, n=10) | 24.4 ms (7/27) | 191 † | 76.0% | 0.260 ◊ |
| 🟣 MLX-Swift | QAT OptiQ int4 | 36.0 (A2 7/28, n=6) | 27.9 ms | 4,592 | 91.0% 🏆 | 0.231 ◊ |
| 🔵 llama.cpp | official QAT q4_0 | unloadable | — | — | — | — |
◊ Tick-window instrument (r4, audited). iOS 27's battery gauge reports in 5% steps, so start/end deltas swing ×2 between identical runs (evidence, all 12 retired cells); J/tok here is instead measured between gauge transitions (2 complete ticks per cell, transition timestamps in the raw JSONs, nominal-start enforced, unplugged). Steps aren't equidistant, so a cell carries ±~10% — the Cactus-uncal 0.222 / Cactus-shipped 0.226 / MLX-OptiQ 0.231 trio is one unresolved cluster; LiteRT < MLX < cluster < llama.cpp are resolved. Core AI is structurally excluded: the equalized per-call budget (2048) exceeds its iOS KV cap (1,024) and the app is jetsammed at setup. † mmap'd weights: clean pages aren't charged to
phys_footprint, so these cells are not comparable with runtimes that wire their weights — llama.cpp's 191 MB hides 2.9 GB of mmap'd GGUF that shows up in residency (3.1 GB). LiteRT-LM is the only arm under a gigabyte on both the footprint and resident columns, which is the honest form of the memory claim. ‡ Patched engine (reference): Apple ships no Gemma-4 bundle andEngineOptions.staticInputBuffersis a local engine patch — but the path is Apple's standardEngineFactory. Its TTFT is the honest cost of S=1 unbatched prefill (Gemma-4's per-layer embeddings force it). ¶ Cactus row = the build they demoted, because it is their best usable. On 2026-07-09 Cactus replaced its default CQ4 and renamed the original to-uncalibrated. The two are speed-identical but the shipped default is reasoning-dead: GSM8K 3.0% on the same one-harness protocol, while the demoted build scores 87.0% — the QAT-class band. Their newer mixed-precision prebuilts (cq3.26/cq2.54) probe at 4%/16% (n=25). Same best-usable rule that puts MLX on OptiQ; the uncalibrated zip is a manual download from the same HF repo. Engine = their Metal GPU default viacactus_init/cactus_complete, cloud-handoff + telemetry forced off, exact engine-reported token counts. Cross-session ratios go through a same-session LiteRT anchor: at matched conditions Cactus-shipped decodes at 0.84× LiteRT (block C, 2026-07-29: 50.0 vs 59.4 — re-confirming the 0.83× the 7/20 control measured).
-
The decode+memory upset survives the fairness fix — and now a 7th arm. LiteRT-LM still beats every loadable arm on decode and every wired-memory arm on footprint (2.2–9.5×). At matched quality (LiteRT 86.0 vs MLX-PTQ 84.0) it is 1.14× faster with 6× less memory. Cactus arrives as the clear #2 on decode — at matched same-session conditions it runs 0.83× LiteRT's rate (¶, anchor-adjusted) at higher GSM8K (87.0 vs 86.0), paying 2.2× the memory and 2.6× the energy.
-
Quality still goes to MLX-OptiQ: 91.0% — +5 pts over the wNa8o8 build LiteRT ships, at 0.66× its decode. No runtime is Pareto-dominant once quality is on the table: speed/memory/energy → LiteRT-LM, quality → MLX-OptiQ, balance → Core AI or Cactus-uncalibrated (Cactus: 0.83× LiteRT's decode at +1 GSM8K pt; Core AI: +2 pts at 0.65×).
-
The Cactus finding is an artifact-lineage story, not an engine story (¶): the engine is genuinely fast (second-fastest decode measured here), and the build its own CLI ships scores 3.0% on GSM8K while the build it demoted scores 87.0%. "Which file did the runtime hand you" is worth 84 points — the sharpest case yet for stating the build per row.
-
Google's official QAT GGUF does not load — llama.cpp aborts on a vocab defect ("empty token at index 237922", reproduced through the latest release b10064; the third-party Q4_K_M loads fine, so it is that file's conversion). The official-QAT row is the measurement: shipping an artifact ≠ shipping a usable artifact. llama.cpp's usable best is also the table's quality floor (76.0%).
-
PTQ→QAT re-measured with stored reports: 84.0 → 91.0 (+7 pts) — supersedes the earlier "78 → 87" claim from the defective-harness era.
-
Energy (battery-delta, 600 s sustained, unplugged): wNa8o8 wins on-device energy too — 24 % more tokens on the same 5 % of battery than MLX-PTQ (0.122 vs 0.151 J/tok), reversing the Mac result where MLX owns the energy Pareto — and it throttles less (76 % vs 64 % of burst rate retained). Core AI jetsams under the standard deep protocol (its known depth wall — the failed run stays on record per fairness rule #4); measured via a shallow-rep variant (
--max-tokens 192, depth kept under the wall) it lands at 0.352 J/tok — a favorable-bias lower bound that still spends ~2.9× LiteRT's energy per token. llama.cpp is the energy floor at 0.483 J/tok: it pulls ~2× any other arm's average power (9.8 W), hits the thermal ceiling hardest, and keeps the least of its burst rate under sustained load (54 %, vs LiteRT 76 / OptiQ 67 / MLX-PTQ 64 / Cactus 57 / Core AI 56) — the same 1.9× llama-vs-MLX gap the Mac shows, amplified by the phone's thermal loop. Cactus lands at 0.322 J/tok (2026-07-20 capture, 600 s standard deep protocol, 10 % battery in one window at 9.2 W — the second-highest draw; sustained 28.7 tok/s = 57 % of burst; entered the window atnominalwhere the 07-19 arms entered atfair, a slightly favorable regime — disclosed): its near-LiteRT burst speed costs 2.6× LiteRT's energy per token. The spread on one phone (0.122 → 0.483, 4.0×) is the campaign's cleanest evidence that runtime engineering, not silicon, sets the on-device energy bill. -
The upset — Gemma 4 E2B (re-verified under the fair protocol): Google's LiteRT-LM (wNa8o8 QAT, GPU, its native
.litertlm) beats MLX-Swift on decode (61.1 vs 49.1 warm), uses ~6× less memory (497 vs 3,010 MB median footprint — and it is the only arm under 1 GB on the resident column too), and now wins prefill on the unified instrument (3,513 vs 3,274 tok/s at p=1024, same task, same session — the old cross-instrument prefill ranking is retired). The purpose-built runtime wins on its own format — and on the audited tick-window instrument it also leads iPhone energy (0.147 vs 0.182 J/tok; the Mac's GPU-only basis flips to MLX).
| Runtime | Decode tok/s | Peak MB |
|---|---|---|
| 🟣 MLX-Swift | 61.2 🏆 | 1,279 |
| 🔵 llama.cpp | 39.1 | 1,479 |
| 🟠 CoreML/ANE | 27.9 | 241 🏆 |
⚠️ Debug-build captures (fairness-rules #7); a Release re-capture is pending. The CoreML/ANE arm is off by default in current builds (the author's own library, kept out of the neutral default; its chunked-MLKV 241 MB footprint stands as the memory reference). No LiteRT-LM row at this size — a Qwen3-0.6B.litertlmmatch is wired and pending.
- Counting: MLX / llama.cpp / LiteRT-LM report exact tokenizer tokens (LiteRT-LM via
getBenchmarkInfo); CoreML/ANE counts streamed pieces (≈ tokens). Since the r2 harness every arm is capped at the same 128-token budget; decode tok/s is a rate, so the head-to-head holds. - Fully automated, side-loaded via
devicectlheadless mode — nothing typed on the phone, same methodology as the desktop rows. - Coming next: Apple Foundation Models, chart refresh for the new Gemma table, more models and more iPhones / iPads. One row is a great PR.
How the LiteRT-LM row was measured (updated 2026-07-30):
google-ai-edge/LiteRT-LMrunninglitert-community/gemma-4-E2B-it.litertlm(wNa8o8 QAT) on the Metal GPU backend, via the in-treeMediaPipeRuntimeadapter — same headless harness + prompt as every other row. Since the r2 harness the row is capped at the same 128-token budget as every arm and timed on the harness wall-clock column; since r3 the engine's own prefill/decode counters (Conversation.getBenchmarkInfo) are kept on capped runs too, so counts are exact, not estimated. Memory = jetsam-chargedphys_footprint. First-ever load builds device caches (~112 s once); cold loads after that are 1.4–3.6 s. LiteRT-LM is vendored as a local SwiftPM package (scripts/bootstrap.shclones it withGIT_LFS_SKIP_SMUDGE=1; the released package trips SwiftPM's unsafe-flags rule via its-all_load).How the CoreML/ANE rows were measured:
john-rocky/CoreML-LLMon the Neural Engine (computeUnits: .cpuAndNeuralEngine) — Gemma 4 E2B via the chunked.mlmodelcpath, Qwen 3.5 2B viaQwen35MLKVGenerator(chunked MLKV, hence the 241 MB). Decode counts streamed pieces (≈ tokens); first-load ANE compilation makes its load time high (and it's the lowest-throughput runtime — the ANE trades speed for memory).Decode tok/s is the headline number; the full per-run audit (prefill, TTFT, inter-token jitter, memory) lives in
RESULTS.md. The 2026-07-18 Gemma-4-E2B session's raw per-run JSONs and audit trail (including the thermally-excluded captures) live inresults/raw/2026-07-18-gemma4-bestquant/pending the RESULTS.md importer's extension to that format.
The table above is cold-burst speed. Run the same model continuously and it flips: the GPU runtimes (MLX, LiteRT-LM) heat up and shed ~50–60% of their throughput under sustained load, while the ANE barely moves (retains ~65%). MLX crosses the 50%-lost line within ~60 s; LiteRT-LM is more thermally resilient early — it still holds ~53% of its burst rate at 1 min and only crosses 50% near the 4-min mark — but settles in the same place. The ANE draws ~half the package power (measured on Mac via powermetrics — iOS doesn't expose power counters to third-party apps), so it heats slowly and the SoC doesn't throttle it.
| Gemma 4 E2B, iPhone 17 Pro | Burst tok/s | Sustained (10 min) | Retained |
|---|---|---|---|
| CoreML / ANE | 33 | 22 | 67% |
| MLX / GPU | 48 | 18 | 38% |
| LiteRT-LM / GPU | 56 | 27 | 48% |
Two independent GPU runtimes collapsing the same way is a GPU-thermal property of the phone, not a runtime quirk. MLX ends up below the ANE; LiteRT keeps only a slim lead after shedding half its speed. The GPU wins the sprint; the ANE wins the marathon — and it frees the GPU for the rest of the app.
Method: 600 s continuous generation, cold (
nominal) start, unplugged, tg128; decode rate from a rolling window. Raw JSONL inresults/raw/iphone17pro-*-energy-tg128.jsonl; redraw withscripts/throttle_chart.py(curves table viascripts/throttle_curve.py). LiteRT-LM has no output-token cap (longer per-call) and that run started atfairthermal; CoreML-LLM uses sliding-window attention (bounded context), part of why its decode stays flat.
The throttle section above is text decode. The next axis runs a vision-language model on the live camera, continuously for 10 minutes — the workload an always-on "point the phone at the world" feature actually is — and asks the same question: does the GPU melt while the ANE holds?
Same phone, same scene, Qwen3-VL 2B on both paths (both run today):
- GPU —
MLXVLMRuntime(MLX/Metal),mlx-community/Qwen3-VL-2B-Instruct-4bit. - ANE —
CoreMLVLMRuntime(CoreML,.cpuAndNeuralEngine) drivingjohn-rocky/CoreML-LLM's real Qwen3-VL pipeline (vision encoder → chunked INT8 decoder), modelmlboydaisuke/qwen3-vl-2b-coreml.
The app gains a Camera tab: pick the backend, point it at a dense scene, hit
Start. The HUD overlays sustained FPS, thermal state, battery, ANE residency
live (it doubles as the screen-record surface for the demo clip). Each session
logs sustained FPS, per-inference TTFT, ANE residency (MLComputePlan), peak
thermal and whole-system power, plus the FPS-and-heat time series the chart is
drawn from:
# Camera tab → backend → 10 min → Start (run once per backend, same scene)
python3 scripts/vlm_throttle_chart.py # → docs/charts/vlm-camera-throttle.pngMethod, fairness rules, the ANE-residency measurement, and the clip protocol:
methodology/vlm-camera-ios.md. Numbers land
once the runs are captured on device — a paired ANE/GPU session is a great PR.
The same harness on a laptop-class chip, for scale. No runtime wins everything here — each optimises a different corner of the throughput / memory / energy / streaming box.
Gemma 4 E2B, best-available builds — throughput × energy (2026-07-19, decode-window J/token, warm loads):
| Build | J/tok (decode) | W (decode) | tok/s |
|---|---|---|---|
| 🟣 MLX PTQ 4-bit | 0.090 🏆 | 14.6 | 177.8 🏆 |
| 🟣 MLX QAT OptiQ | 0.106 | 14.6 | 149.5 |
| 🔴 LiteRT wNa8o8 (WebGPU path) | 0.154 | 22.2 | 155.0 |
| 🔵 llama.cpp Q4_K_M | 0.170 | 20.5 | 127.1 |
| 🍎 Core AI own int4 (patched, S=1 window) | ~0.33 | 18.9 | 53 eff. |
- MLX owns the Mac energy Pareto — fastest and most efficient, at the lowest package power. The +7-pt GSM8K of OptiQ costs +18 % J/tok.
- The LiteRT row does not answer the int8-activation energy question: Mac LiteRT runs the WebGPU→Metal path, a different efficiency class from the iPhone's native path (where wNa8o8 wins decode+memory). That question needs the iPhone battery-delta bench (planned as part 2).
- Core AI pays its S=1 prefill wall in energy too on the Mac (~2.2× MLX's J/tok at 0.3× the speed) — patched-engine reference row, whole-window measurement.
- Whole-system
powermetricson an idle desktop; decode-window attribution (the trailing generation phase of the sample train) so per-arm load differences don't dilute the number. Raw rows:results/raw/m4max-*-sustained-energy.jsonl.
Older cross-runtime observations (Apple FM 2× efficiency, CoreML/ANE memory-vs-J/tok inversion) belong to the 4-backend charts below, measured 2026-05 with full-window attribution:
| Tables for the exact numbers live below. |
Regenerate after adding rows: python scripts/generate_charts.py.
One device, four runtimes, multiple models. Decode tok/s is the primary headline number; the full table (prefill, TTFT, peak memory, per-run audit trail) lives in
RESULTS.md. Read the Headline observations section before drawing conclusions — the runtime ranking is model-size-dependent.
| Logical model | Params | n | mlx-swift (Q4) | llama.cpp (Q4_K_M) | coreml-llm | litert-lm (.litertlm) |
|---|---|---|---|---|---|---|
| Qwen 2.5 0.5B | 0.5 B | 3 | 531.1 | 297.1 | 181.2 (FP16) | n/a |
| Qwen 3.5 0.8B | 0.8 B | 3 | 421.1 | 201.1 | 58.2 (INT8) | n/a |
| Qwen 3.5 2B | 2 B | 3 | 291.9 | 149.7 | 35.0 (INT8) | n/a |
| Gemma 4 E2B | 2 B | 3 | 185.4 | 119.2 | 32.5 (INT4 palettized) | pending |
| Gemma 4 E4B | 4 B | 3 | 113.5 | 80.5 | not run | pending |
litert-lmcolumn: pending = adapter wired againstgoogle-ai-edge/LiteRT-LMv0.12.0, M4 Max run not yet captured (seeRESULTS.md/Yardstick_USER_RUNS.md). n/a = no official.litertlmat this exact Qwen size —litert-communityships Qwen3-0.6B and Qwen3.5-4B alongside Gemma (it is not Gemma-only); the 0.5B/0.8B/2B sizes in this table just have no matching LiteRT artifact. A Qwen3-0.6B cross-runtime row is coming. For reference, Google's E2B model card reports 56.5 tok/s on iPhone 17 Pro GPU — a vendor figure on a different device, not an M4 Max Yardstick measurement.
→ MLX-Swift now wins decode on every cell — 1.4×–1.8× over llama.cpp — after upstream mlx-swift-lm shipped Qwen + Gemma kernel updates in early 2026 (the Qwen rows roughly tripled vs. the snapshot captured before those landed). The old "llama.cpp Metal always wins small-model decode" rule is no longer true on M4 Max; re-measure before quoting it. CoreML / ANE is the slowest of the three on every cell, in exchange for the dramatic memory savings shown below.
The decode-tok/s table above hides the memory side. Same models, looking at peak working-set instead:
| Logical model | Params | mlx-swift | llama.cpp | coreml-llm | litert-lm |
|---|---|---|---|---|---|
| Qwen 2.5 0.5B | 0.5 B | 390 | 538 | 962 | n/a |
| Qwen 3.5 0.8B | 0.8 B | 600 | 752 | 221 (INT8) | n/a |
| Qwen 3.5 2B | 2 B | 1223 | 1443 | 230 (INT8) | n/a |
| Gemma 4 E2B | 2 B | 2829 | 3212 | 1036 | pending |
| Gemma 4 E4B | 4 B | 4376 | 5150 | — | pending |
→ "CoreML/ANE wins memory" is true once the chunked MLKV layout kicks in. At 0.5 B params MLX-Swift is still smaller (413 MB vs CoreML's 959 MB monolithic FP16); from 0.8 B onward, CoreML's chunked MLKV path (Qwen35MLKVGenerator: mmap'd embed sidecar + on-demand ANE chunks) holds the process RSS roughly flat — 206 MB at 0.8 B, 215 MB at 2 B — while MLX and llama.cpp scale linearly with parameter count.
The number nobody else publishes: how many joules does each backend burn per generated token? Captured via scripts/measure_energy.py which co-runs powermetrics (whole-system, package power = CPU + GPU + ANE) and clips the sample window to the bench's reported active time.
The ANE path draws ~half the GPU path's package power at full decode (12.7 W vs ~24.7 W) — the same power gap that makes the GPU runtimes thermally throttle on iPhone while the ANE holds its rate (see the sustained-throttle section above).
| Runtime | Avg pkg power (W) | Energy / 512-tok run (J) | J / token |
|---|---|---|---|
| apple-fm (system model) | 7.6 | 67.4 | 0.11 |
| mlx-swift (4-bit MLX) | 24.7 | 123.0 | 0.24 |
| llama.cpp (Q4_K_M, GGUF) | 24.5 | 126.3 | 0.25 |
| coreml-llm (INT4 palettized, ANE) | 12.7 | 244.9 | 0.48 |
→ Energy ranking inverts the decode-tok/s ranking. Apple FM is 2× more efficient per token than the GPU-backed runtimes despite producing tokens at ~half the rate. CoreML/ANE has the lowest instantaneous power (12.7 W) but is the worst J/tok at 4× Apple FM, because the slower decode (32 tok/s) keeps the package powered up much longer. MLX-Swift and llama.cpp draw the most W (GPU) but produce tokens fast enough to break even at ~0.24 J/tok. Whole-system measurement includes the idle baseline so all four numbers slightly inflate per-token energy — useful for ranking, not for absolute attribution. iPhone energy uses the 1 %-battery-step API instead (different methodology, similar table shape).
llama.cpp (Q4_K_M GGUF, M4 Max, short-chat)
| Model | Params | n | TTFT (ms) | Decode tok/s | Peak Mem (MB) |
|---|---|---|---|---|---|
| Qwen 2.5 0.5B | 0.5 B | 3 | 22 | 297.1 | 538 |
| Qwen 3.5 0.8B | 0.8 B | 3 | 22 | 201.1 | 752 |
| Llama 3.2 1B |
1.0 B | 3 | 25 | 285.9 | 1022 |
| Qwen 3.5 2B | 2 B | 3 | 29 | 149.7 | 1443 |
| Gemma 4 E2B | 2 B | 3 | 41 | 119.2 | 3212 |
| Gemma 4 E4B | 4 B | 3 | 62 | 80.5 | 5150 |
mlx-swift (Q4 / MLX, M4 Max, short-chat)
| Model | Params | n | TTFT (ms) | Decode tok/s | Peak Mem (MB) |
|---|---|---|---|---|---|
| Qwen 2.5 0.5B | 0.5 B | 3 | 21 | 531.1 | 390 |
| Qwen 3.5 0.8B | 0.8 B | 3 | 36 | 421.1 | 600 |
| Qwen 3.5 2B | 2 B | 3 | 42 | 291.9 | 1223 |
| Gemma 4 E2B | 2 B | 3 | 68 | 185.4 | 2829 |
| Gemma 4 E4B | 4 B | 3 | 90 | 113.5 | 4376 |
coreml-llm (CoreML / ANE, M4 Max, short-chat)
| Model | Params | n | TTFT (ms) | Decode tok/s | Peak Mem (MB) |
|---|---|---|---|---|---|
| LFM 2.5 350M |
0.35 B | 1 | 383 | 58.9 | 98 |
| Qwen 2.5 0.5B | 0.5 B | 3 | 171 | 181.2 | 962 |
| Qwen 3.5 0.8B | 0.8 B | 3 | 405 | 58.2 | 221 |
| Qwen 3.5 2B | 2 B | 3 | 665 | 35.0 | 230 |
| Gemma 4 E2B | 2 B | 3 | 525 | 32.5 | 1036 |
→ CoreML/ANE trades throughput for memory: 3-8× less peak working set than MLX-Swift / llama.cpp at the same model size, at ~half the decode tok/s. The Qwen 3.5 0.8B / 2B numbers come from the dedicated Qwen35MLKVGenerator (ANE chunked decode, KV in MLState — public API since CoreML-LLM v1.9.0), not the generic CoreMLLLM.load(from:) path.
Apple FM is a single pre-installed model, so it can't share a "logical model" row with the open-weight runtimes above. It earns its own line as a reference point — the number to beat when "just use the system model" is the alternative.
| Runtime | Model | n | TTFT (ms) | Decode tok/s | Peak Mem (MB, in-process) |
|---|---|---|---|---|---|
| apple-fm | Apple Foundation Model (default, ~3 B params est.) | 3 | 269 | 85.2 | 27 |
Caveats — read before comparing.
- Tokens are estimated (
utf8.count / 4) becauseFoundationModelsdoes not expose the tokenizer. Treat decode tok/s as ±20%; the other runtimes report counts from their actual tokenizer. - Peak memory is in-process only. The model lives in Apple's system process, not ours, so 27 MB is the harness overhead — not the true model footprint. Use Activity Monitor /
powermetricsfor the system-wide picture. - Quant is Apple-internal. Community reverse-engineering puts it at ~2-bit base weights + 4-bit task adapters; Apple has not published numbers. Don't read the decode tok/s as a comment on any specific quant choice.
Full results — by model, by runtime, full per-run audit trail →
This table is the repo. The easiest possible contribution is one new row. All three of these are equally valuable:
- A new device. Run the existing models on your iPhone / iPad / Mac. Tooling in
Yardstick_USER_RUNS.md. The "Devices wanted" list at the bottom ofRESULTS.mdis the shortlist. - A new model. Drop the model id into the
ModelCatalogfor the runtime that can load it. - A new runtime. Wire it up in
ios/BenchmarkApp/Sources/Runtimes/following theLLMRuntimeprotocol; the harness will pick it up.
Workflow once you have the build set up:
# 1. Run 3 times to get a stable median:
for run in 1 2 3; do
yardstick run --task short-chat \
--runtime mlx-swift \
--model <id-or-hf-repo> \
--output results/raw/<device>-<runtime>-<model>-short-chat-run${run}.jsonl
done
# 2. Regenerate the tables — they're auto-built from JSONL:
python scripts/render_results.py
# 3. Commit the JSONLs + the updated RESULTS.md, open a PR.CI runs python scripts/render_results.py --check on every PR — it fails if the JSONLs and the tables disagree, so the human-edited section of RESULTS.md cannot drift out of sync with the raw data.
Full step-by-step (build, model picker, device-specific gotchas) lives in CONTRIBUTING.md.
Per (runtime, model, device, build) tuple:
- Speed — TTFT, prefill
tok/s, decodetok/s, sustained-decode drift over 512+ tokens. - Memory — baseline, peak during decode, after-generation.
- Thermal — initial / peak / final state across the run.
- Jitter — inter-token latency
p50/p95/p99ms, captured from the gap between consecutive.chunkevents. Surfaces the worst-case stall a chat UI will perceive even when the average decode rate looks smooth. - Energy — joules per token. iOS uses the 1%-battery-step API; Mac uses
scripts/measure_energy.py(wrapspowermetrics, see "Optional: capture Mac energy" below). - Lifecycle — survives background → foreground, cancellation latency, streaming.
- Quality (roadmap) — WER / CER for ASR, perplexity / MMLU for LLM, byte-identical comparison vs Python references.
Methodology lives under methodology/. The numbers we publish follow methodology/fairness-rules.md.
sudo python scripts/measure_energy.py run \
--task short-chat --runtime mlx-swift \
--model mlx-community/gemma-4-e2b-it-4bit \
--output results/raw/<device>-<runtime>-<model>-<task>-energy.jsonlThe wrapper starts powermetrics in the background, runs yardstick,
stops powermetrics, then patches the JSONL with energyJoules,
averagePackagePowerW, and energyJoulesPerToken. Numbers are
whole-system — run on an idle desktop and use them to compare
runtimes on the same Mac, not Macs to each other.
The iOS app's History → ••• → Export all (JSONL) sheet hands you a single newline-delimited file. AirDrop it to your Mac, then:
python scripts/import_ios_export.py ~/Downloads/yardstick-*.jsonl
python scripts/render_results.pyThe import script splits the bundle into one
results/raw/<device>-<runtime>-<model>-<task>-runN.jsonl per row,
re-keying the device label so render_results.py recognises it.
Yardstick/
├── Package.swift SPM: YardstickKit library + `yardstick` Mac CLI
├── apple/
│ └── YardstickCLI/ Mac command-line runner
├── ios/
│ └── BenchmarkApp/ On-device iOS app (`.xcodeproj`)
├── android/ adb-driven Android lane (LiteRT-LM, llama.cpp; Pixel 8a)
├── runtimes/ Per-runtime notes (adapters, gotchas, version pins)
├── devices/ Per-device pages (chip, RAM, OS, build, signing)
├── methodology/ How we measure each axis fairly
├── matrices/ Standing matrix cell files (./bench matrix|regress)
├── models/ Curated model catalog
├── prompts/ Standardized prompts per task (text/ = canonical bytes)
└── results/
├── raw/ JSONL dumps per run
├── summary/ machine-readable accumulation (build_summary.py)
├── regression-reports/ release-over-release verdicts (regression_report.py)
└── (tables generated into RESULTS.md + LEADERBOARD.md)
Status (July 2026): the SPM CLI runs end-to-end — no Xcode target required. mlx-swift#349 (the MLX Metal bundle not being emitted by
swift buildfrom a downstream package) is resolved on the pinned mlx-swift 0.31.3 with current Swift:swift buildnow emitsmlx-swift_Cmlx.bundle(carryingdefault.metallib) next to theyardstickbinary, soswift run yardstick run …loads MLX and runs. Build Release for real numbers — a Debug build adds large per-token host overhead and understates decode (fairness-rules #7).
$ swift run yardstick list
# Real numbers need a Release build:
$ swift run -c release yardstick run \
--task short-chat \
--runtime mlx-swift \
--model mlx-community/Qwen3-0.6B-4bit \
--output results/raw/<device>-mlx-qwen3-0.6b.jsonlIf a Release build ever fails with
unable to spawn … Metal.xctoolchain/usr/bin/metal (No such file or directory), the on-demand Metal toolchain mount changed (a reboot or Xcode update remounts it under a new path) and SwiftPM's cached build manifest still points at the old one. Clear the manifest and rebuild —rm -rf .build/out/Intermediates.noindex/XCBuildData— which re-derives the current toolchain path (a fullswift package cleanalso works, but recompiles everything). Only re-download the toolchain (xcodebuild -downloadComponent MetalToolchain) if the asset itself is gone. Unrelated to the harness.
cd ios/BenchmarkApp
./scripts/bootstrap.sh # downloads llama.xcframework + Anemll source
open BenchmarkApp.xcodeproj # set your Team in Signing & Capabilities
# ⌘R on a connected iPhoneFirst launch downloads the chosen model (default: mlx-community/gemma-4-e2b-it-4bit, ~1.3 GB) into the app's Documents directory. Use the picker to swap.
| Runtime | Adapter | Wire-up |
|---|---|---|
| MLX Swift | MLXRuntime.swift |
SPM (mlx-swift-lm) |
| llama.cpp | LlamaCppRuntime.swift |
vendored llama.xcframework (bootstrap.sh) |
| CoreML (swift-transformers) | CoreMLRuntime.swift |
SPM (swift-transformers Models + Generation) |
| LiteRT-LM | MediaPipeRuntime.swift |
SPM (google-ai-edge/LiteRT-LM ≥ 0.13, product LiteRTLM); #if canImport(LiteRTLM)-gated |
| ExecuTorch | ExecuTorchRuntime.swift |
SPM (pytorch/executorch swiftpm-* branch) |
| ANEMLL | AnemllRuntime.swift |
local SPM via vendored Anemll/ (bootstrap.sh) |
| Apple Foundation Models | AppleFMRuntime.swift |
system framework, #if canImport(FoundationModels) (macOS 26 / iOS 26) |
Adapters whose framework isn't present at build time are gated with #if canImport(...) and fall back to a clear "not added" error rather than failing the build.
Verified in-tree:
devices/mac-m4-max.md— Apple M4 Max (macOS 26)devices/macbook-air-m3.md— MacBook Air M3, 16 GB (macOS 26)devices/iphone-17-pro.md— iPhone 17 Pro (iOS 26)
Community devices wanted. If you have an Apple Silicon device not listed above, the fastest way to contribute a row to RESULTS.md is to:
- Add a
devices/<your-device>.mddescribing the hardware/OS/build. - Run the app or CLI per
methodology/measurement.md. - PR the resulting
results/raw/<device>-*.jsonland the updatedRESULTS.mdrows.
Devices we'd love numbers for:
- iPhone 15 Pro / 16 Pro / 17 Pro Max / 17 Air
- iPad Pro M2 / M4
- MacBook Pro M1 / M2 / M3 / M4 (Pro / Max)
- Mac Studio Ultra (M2 Ultra / M3 Ultra)
- Mac mini M2 / M4
| Backend | Build on Mac | Run on Mac | Notes |
|---|---|---|---|
| MLX Swift LM | ✅ | ✅ | Native SPM macOS — swift run yardstick runs end-to-end. mlx-swift 0.31.3 emits the Metal bundle next to the CLI binary, so the old #349 Xcode-target workaround is no longer needed. |
| llama.cpp | ✅ | ✅ | macos-arm64_x86_64 slice in Vendored/llama.xcframework. CLI uses LD_RUNPATH_SEARCH_PATHS to resolve the framework at runtime. |
| CoreML (CoreMLLLM) | ✅ | ✅ (some models) | macOS 15+. Models with the single-top-level .mlpackage layout (e.g. LFM 2.5 350M) auto-download from HF and run; the chunked / multi-.mlpackage repos (e.g. mlboydaisuke/qwen3.5-0.8B-CoreML) need upstream CoreMLLLM work to load. |
| ExecuTorch | ✅ | ⏸ | Build path is clean; current ET-community models ship SentencePiece tokenizer.model but ET's hf_tokenizer.cpp expects HF-format tokenizer.json. Needs a model with HF tokenizer or an ET-side SentencePiece adapter. |
| ANEMLL | ✅ | ⏸ | Build path is clean; swift-huggingface.HFDownloader fails on .mlmodelc/ directory-shaped HF repos. Needs upstream downloader work. |
| LiteRT-LM | ✅ | ⏸ | google-ai-edge/LiteRT-LM v0.12.0 ships ios-arm64 + macos-arm64 slices, wired via SPM (product LiteRTLM, macOS 12+). Build path clean; M4 Max run pending. Watch the package's -all_load for duplicate-symbol clashes with the vendored llama/executorch static libs (fall back to scoped -force_load). |
The standing-benchmark harness now lives in its own repo:
edge-llm-bench — carved out
2026-08-17 with the v0.15.0 → v0.16.0 regression run as its founding
baseline. That repo is canonical for the harness going forward; this one
remains the measurement archive (published tables, full raw history, the
./reproduce registry). The harness copy here still works — runbooks in
docs/OPERATIONS.md, entrypoint ./bench, standings
in LEADERBOARD.md.
- Phase 1 — repo rename, top-level SPM (
YardstickKit+yardstickCLI), Mac CLI builds clean, README + device pages, methodology docs, iOS app intact. - Phase 2 — Mac CLI runs end-to-end via plain SPM (
swift run yardstick; mlx-swift #349 resolved on 0.31.3 — no Xcode-target workaround), first M4 Max numbers committed toRESULTS.md. - Phase 2.5 — All 5 buildable backends (MLX, llama.cpp, CoreML, ExecuTorch, ANEMLL) wired into the Mac tool target; first cross-backend row (Gemma 4 E2B: MLX vs llama.cpp).
- Phase 3 (in progress) — fill remaining adapter row gaps (downloader + model-format work, mostly upstream), MacBook Air M3 + iPhone 17 Pro numbers via
[Yardstick_USER_RUNS.md](../Yardstick_USER_RUNS.md). - Phase 4 — quality / accuracy tasks: WER + CER (reusing
swift-transformersWhisper normalizer), perplexity, MMLU subset. ASR + TTS adapters (WhisperKit, Apple Speech, system TTS). - Phase 5 — public results dashboard, regeneration CI, comparison plots.
MIT, see LICENSE.