Llama-v2-7B-Chat: Optimized for Mobile Deployment

State-of-the-art large language model useful on a variety of language understanding and generation tasks

Llama 2 is a family of LLMs. The "Chat" at the end indicates that the model is optimized for chatbot-like dialogue. The model is quantized to 4-bit weights and 16-bit activations making it suitable for on-device deployment. For Prompt and output length specified below, the time to first token is Llama-PromptProcessor-Quantized's latency and average time per addition token is Llama-TokenGenerator-KVCache-Quantized's latency.

This is based on the implementation of Llama-v2-7B-Chat found here. More details on model performance accross various devices, can be found here.

Model Details

• Model Type: Text generation
• Model Stats:
  • Number of parameters: 7B
  • Model size: 3.6GB
  • Model-1 (Prompt Processor): Llama-PromptProcessor-Quantized
  • Max context length: 1024
  • Prompt processor input: 1024 tokens
  • Prompt processor output: 1024 output tokens + KVCache for token generator
  • Model-2 (Token Generator): Llama-TokenGenerator-KVCache-Quantized
  • Token generator input: 1 input token + past KVCache
  • Token generator output: 1 output token + KVCache for next iteration
  • Decoding length: 1024 (1 output token + 1023 from KVCache)
  • Use: Initiate conversation with prompt-processor and then token generator for subsequent iterations.
  • QNN-SDK: 2.19

Device	Chipset	Target Runtime	Inference Time (ms)	Peak Memory Range (MB)	Precision	Primary Compute Unit	Target Model
Samsung Galaxy S23 Ultra (Android 13)	Snapdragon® 8 Gen 2	QNN Model Library	117.812 ms	66 - 238 MB	UINT16	NPU	Llama-TokenGenerator-KVCache-Quantized
Samsung Galaxy S23 Ultra (Android 13)	Snapdragon® 8 Gen 2	QNN Model Library	2578.521 ms	12 - 17 MB	UINT16	NPU	Llama-PromptProcessor-Quantized

License

• The license for the original implementation of Llama-v2-7B-Chat can be found here.

References

• LLaMA: Open and Efficient Foundation Language Models
• Source Model Implementation

Community

• Join our AI Hub Slack community to collaborate, post questions and learn more about on-device AI.
• For questions or feedback please reach out to us.

Usage and Limitations

Model may not be used for or in connection with any of the following applications:

• Accessing essential private and public services and benefits;
• Administration of justice and democratic processes;
• Assessing or recognizing the emotional state of a person;
• Biometric and biometrics-based systems, including categorization of persons based on sensitive characteristics;
• Education and vocational training;
• Employment and workers management;
• Exploitation of the vulnerabilities of persons resulting in harmful behavior;
• General purpose social scoring;
• Law enforcement;
• Management and operation of critical infrastructure;
• Migration, asylum and border control management;
• Predictive policing;
• Real-time remote biometric identification in public spaces;
• Recommender systems of social media platforms;
• Scraping of facial images (from the internet or otherwise); and/or
• Subliminal manipulation