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Qwen3.8-27B on the iPhone 18 Neural Engine at 15–70 tok/s (1.5 bpw)

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In short

Decoding Peaks at 70 Tok/s with Predictable Context.** Apple's Neural Engine on the iPhone 18 is capable of processing 70 tokens per second (tok/s) with a decoding speed of 15-60 tps. This performance is achieved with a 24K context size and both Key/Value pairs stored in integer format (int8). The Apple Neural Engine is noted as fast, indicated by the emoji "🚀." Qwen 3.8-27B on iPhone 18 Apple Neural Engine.** This model runs on the iPhone 18 with the Apple Neural Engine, achieving a decoding speed of 15-60…

Key points

  • Decoding Peaks at 70 Tok/s with Predictable Context.** Apple's Neural Engine on the iPh…: Decoding Peaks at 70 Tok/s with Predictable Context.** Apple's Neural Engine on the iPhone 18 is capable of processing 70 tokens per second (tok/s) with a decoding speed of 15-60 tps.
  • This performance is achieved with a 24K context size and both Key/Value pairs stored in i…: This performance is achieved with a 24K context size and both Key/Value pairs stored in integer format (int8).
  • The Apple Neural Engine is noted as fast, indicated by the emoji "🚀." **Qwen 3.8-27B on…: The Apple Neural Engine is noted as fast, indicated by the emoji "🚀." **Qwen 3.8-27B on iPhone 18 Apple Neural Engine.** This model runs on the iPhone 18 with the Apple Neural Engine, achieving a decoding speed of 15-60 tps.

Sources checked by our analysis pipeline: 1

Anemll on X: "Confirmed 24K context on iPhone with both K/V on int8. Delta net stays FP16. Decoding also peaks at 70 tok/s with easy to predict context.

Apple Neural Engine on A20 is fast 🚀"

Confirmed 24K context on iPhone with both K/V on int8. Delta net stays FP16. Decoding also peaks at 70 tok/s with easy to predict context.

Apple Neural Engine on A20 is fast 🚀

Qwen 3.8- 27B on iPhone 18 Apple Neural Engine.

Added draft model , dflash-2 at ~ 2.8 bpw ( mixed 2-4 vector quantization with small drop in acceptance rate)

Base is @PrismML Bonsai-2, 1.585 bpw requantized to 1.5 bpw ( VQ 6 bits per 4 weights)

Decoding speed is 15-60 tps.

Confirmed 24K context on iPhone with both K/V on int8. Delta net stays FP16. Decoding also peaks at 70 tok/s with easy to predict context.

Apple Neural Engine on A20 is fast 🚀

Qwen 3.8- 27B on iPhone 18 Apple Neural Engine.

Added draft model , dflash-2 at ~ 2.8 bpw ( mixed 2-4 vector quantization with small drop in acceptance rate)

Base is @PrismML Bonsai-2, 1.585 bpw requantized to 1.5 bpw ( VQ 6 bits per 4 weights)

Decoding speed is 15-60 tps.

Original source: twitter.com

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