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HomeSoftware DevelopmentMassive Language Fashions On-Gadget with MediaPipe and TensorFlow Lite

Massive Language Fashions On-Gadget with MediaPipe and TensorFlow Lite



Posted by Mark Sherwood – Senior Product Supervisor and Juhyun Lee – Employees Software program Engineer

TensorFlow Lite has been a strong instrument for on-device machine studying since its launch in 2017, and MediaPipe additional prolonged that energy in 2019 by supporting full ML pipelines. Whereas these instruments initially centered on smaller on-device fashions, at present marks a dramatic shift with the experimental MediaPipe LLM Inference API.

This new launch allows Massive Language Fashions (LLMs) to run absolutely on-device throughout platforms. This new functionality is especially transformative contemplating the reminiscence and compute calls for of LLMs, that are over 100 occasions bigger than conventional on-device fashions. Optimizations throughout the on-device stack make this potential, together with new ops, quantization, caching, and weight sharing.

The experimental cross-platform MediaPipe LLM Inference API, designed to streamline on-device LLM integration for internet builders, helps Net, Android, and iOS with preliminary assist for 4 overtly obtainable LLMs: Gemma, Phi 2, Falcon, and Secure LM. It offers researchers and builders the pliability to prototype and check well-liked overtly obtainable LLM fashions on-device.

On Android, the MediaPipe LLM Inference API is meant for experimental and analysis use solely. Manufacturing functions with LLMs can use the Gemini API or Gemini Nano on-device by way of Android AICore. AICore is the brand new system-level functionality launched in Android 14 to offer Gemini-powered options for high-end gadgets, together with integrations with the most recent ML accelerators, use-case optimized LoRA adapters, and security filters. To begin utilizing Gemini Nano on-device together with your app, apply to the Early Entry Preview.

LLM Inference API

Beginning at present, you may check out the MediaPipe LLM Inference API through our internet demo or by constructing our pattern demo apps. You possibly can experiment and combine it into your initiatives through our Net, Android, or iOS SDKs.

Utilizing the LLM Inference API permits you to deliver LLMs on-device in only a few steps. These steps apply throughout internet, iOS, and Android, although the SDK and native API might be platform particular. The next code samples present the net SDK.

1. Decide mannequin weights suitable with certainly one of our supported mannequin architectures 

 

2. Convert the mannequin weights right into a TensorFlow Lite Flatbuffer utilizing the MediaPipe Python Package deal

from mediapipe.duties.python.genai import converter 

config = converter.ConversionConfig(...)
converter.convert_checkpoint(config)

 

3. Embody the LLM Inference SDK in your software

import { FilesetResolver, LlmInference } from
"https://cdn.jsdelivr.web/npm/@mediapipe/tasks-genai”

 

4. Host the TensorFlow Lite Flatbuffer alongside together with your software.

 

5. Use the LLM Inference API to take a textual content immediate and get a textual content response out of your mannequin.

const fileset  = await
FilesetResolver.forGenAiTasks("https://cdn.jsdelivr.web/npm/@mediapipe/tasks-genai/wasm");
const llmInference = await LlmInference.createFromModelPath(fileset, "mannequin.bin");
const responseText = await llmInference.generateResponse("Hi there, good to fulfill you");
doc.getElementById('output').textContent = responseText;

Please see our documentation and code examples for an in depth stroll by way of of every of those steps.

Listed here are actual time gifs of Gemma 2B working through the MediaPipe LLM Inference API.

moving image of Gemma 2B running on-device in browser via the MediaPipe LLM Inference API
Gemma 2B working on-device in browser through the MediaPipe LLM Inference API

moving image of Gemma 2B running on-device on iOS (left) and Android (right) via the MediaPipe LLM Inference API
Gemma 2B working on-device on iOS (left) and Android (proper) through the MediaPipe LLM Inference API

Fashions

Our preliminary launch helps the next 4 mannequin architectures. Any mannequin weights suitable with these architectures will work with the LLM Inference API. Use the bottom mannequin weights, use a neighborhood fine-tuned model of the weights, or wonderful tune weights utilizing your personal knowledge.

 Mannequin

 Parameter Dimension

 Falcon 1B

 1.3 Billion

 Gemma 2B

 2.5 Billion

 Phi 2

 2.7 Billion

 Secure LM 3B

 2.8 Billion

Mannequin Efficiency

By means of vital optimizations, a few of that are detailed under, the MediaPipe LLM Inference API is ready to ship state-of-the-art latency on-device, specializing in CPU and GPU to assist a number of platforms. For sustained efficiency in a manufacturing setting on choose premium telephones, Android AICore can reap the benefits of hardware-specific neural accelerators.

When measuring latency for an LLM, there are a couple of phrases and measurements to contemplate. Time to First Token and Decode Velocity would be the two most significant as these measure how shortly you get the beginning of your response and the way shortly the response generates as soon as it begins.

 Time period

 Significance

 Measurement

 Token

LLMs use tokens moderately than phrases as inputs and outputs. Every mannequin used with the LLM Inference API has a tokenizer constructed wherein converts between phrases and tokens.

100 English phrases ≈ 130 tokens. Nevertheless the conversion depends on the particular LLM and the language.

 Max Tokens

The utmost complete tokens for the LLM immediate + response.

Configured within the LLM Inference API at runtime.

 Time to First Token

Time between calling the LLM Inference API and receiving the primary token of the response.

Max Tokens / Prefill Velocity

 Prefill Velocity

How shortly a immediate is processed by an LLM.

Mannequin and gadget particular. Benchmark numbers under.

 Decode Velocity

How shortly a response is generated by an LLM.

Mannequin and gadget particular. Benchmark numbers under.

The Prefill Velocity and Decode Velocity are depending on mannequin, {hardware}, and max tokens. They’ll additionally change relying on the present load of the gadget.

The next speeds had been taken on excessive finish gadgets utilizing a max tokens of 1280 tokens, an enter immediate of 1024 tokens, and int8 weight quantization. The exception being Gemma 2B (int4), discovered right here on Kaggle, which makes use of a blended 4/8-bit weight quantization.

Benchmarks

Graph showing prefill performance in tokens per second across WebGPU, iOS (GPU), Android (GPU), and Android (CPU)

Graph showing decode performance in tokens per second across WebGPU, iOS (GPU), Android (GPU), and Android (CPU)
On the GPU, Falcon 1B and Phi 2 use fp32 activations, whereas Gemma and StableLM 3B use fp16 activations because the latter fashions confirmed higher robustness to precision loss based on our high quality eval research. The bottom bit activation knowledge sort that maintained mannequin high quality was chosen for every. Word that Gemma 2B (int4) was the one mannequin we may run on iOS as a result of its reminiscence constraints, and we’re engaged on enabling different fashions on iOS as properly.

Efficiency Optimizations

To attain the efficiency numbers above, numerous optimizations had been made throughout MediaPipe, TensorFlow Lite, XNNPack (our CPU neural community operator library), and our GPU-accelerated runtime. The next are a choose few that resulted in significant efficiency enhancements.

Weights Sharing: The LLM inference course of includes 2 phases: a prefill section and a decode section. Historically, this setup would require 2 separate inference contexts, every independently managing sources for its corresponding ML mannequin. Given the reminiscence calls for of LLMs, we have added a function that enables sharing the weights and the KV cache throughout inference contexts. Though sharing weights might sound easy, it has vital efficiency implications when sharing between compute-bound and memory-bound operations. In typical ML inference situations, the place weights are usually not shared with different operators, they’re meticulously configured for every absolutely linked operator individually to make sure optimum efficiency. Sharing weights with one other operator implies a lack of per-operator optimization and this mandates the authoring of recent kernel implementations that may run effectively even on sub-optimal weights.

Optimized Absolutely Related Ops: XNNPack’s FULLY_CONNECTED operation has undergone two vital optimizations for LLM inference. First, dynamic vary quantization seamlessly merges the computational and reminiscence advantages of full integer quantization with the precision benefits of floating-point inference. The utilization of int8/int4 weights not solely enhances reminiscence throughput but additionally achieves exceptional efficiency, particularly with the environment friendly, in-register decoding of 4-bit weights requiring just one further instruction. Second, we actively leverage the I8MM directions in ARM v9 CPUs which allow the multiplication of a 2×8 int8 matrix by an 8×2 int8 matrix in a single instruction, leading to twice the velocity of the NEON dot product-based implementation.

Balancing Compute and Reminiscence: Upon profiling the LLM inference, we recognized distinct limitations for each phases: the prefill section faces restrictions imposed by the compute capability, whereas the decode section is constrained by reminiscence bandwidth. Consequently, every section employs completely different methods for dequantization of the shared int8/int4 weights. Within the prefill section, every convolution operator first dequantizes the weights into floating-point values earlier than the first computation, making certain optimum efficiency for computationally intensive convolutions. Conversely, the decode section minimizes reminiscence bandwidth by including the dequantization computation to the principle mathematical convolution operations.

Flowchart showing compute-intensive prefill phase and memory-intensive decode phase, highlighting difference in performance bottlenecks
Through the compute-intensive prefill section, the int4 weights are dequantized a priori for optimum CONV_2D computation. Within the memory-intensive decode section, dequantization is carried out on the fly, together with CONV_2D computation, to reduce the reminiscence bandwidth utilization.

Customized Operators: For GPU-accelerated LLM inference on-device, we rely extensively on customized operations to mitigate the inefficiency brought on by quite a few small shaders. These customized ops enable for particular operator fusions and varied LLM parameters similar to token ID, sequence patch dimension, sampling parameters, to be packed right into a specialised customized tensor used principally inside these specialised operations.

Pseudo-Dynamism: Within the consideration block, we encounter dynamic operations that improve over time because the context grows. Since our GPU runtime lacks assist for dynamic ops/tensors, we go for fastened operations with a predefined most cache dimension. To scale back the computational complexity, we introduce a parameter enabling the skipping of sure worth calculations or the processing of decreased knowledge.

Optimized KV Cache Format: Because the entries within the KV cache in the end function weights for convolutions, employed in lieu of matrix multiplications, we retailer these in a specialised format tailor-made for convolution weights. This strategic adjustment eliminates the need for further conversions or reliance on unoptimized layouts, and due to this fact contributes to a extra environment friendly and streamlined course of.

What’s Subsequent

We’re thrilled with the optimizations and the efficiency in at present’s experimental launch of the MediaPipe LLM Inference API. That is simply the beginning. Over 2024, we’ll increase to extra platforms and fashions, provide broader conversion instruments, complimentary on-device elements, excessive stage duties, and extra.

You possibly can try the official pattern on GitHub demonstrating all the things you’ve simply discovered about and browse by way of our official documentation for much more particulars. Regulate the Google for Builders YouTube channel for updates and tutorials.

Acknowledgements

We’d wish to thank all group members who contributed to this work: T.J. Alumbaugh, Alek Andreev, Frank Ban, Jeanine Banks, Frank Barchard, Pulkit Bhuwalka, Buck Bourdon, Maxime Brénon, Chuo-Ling Chang, Lin Chen, Linkun Chen, Yu-hui Chen, Nikolai Chinaev, Clark Duvall, Rosário Fernandes, Mig Gerard, Matthias Grundmann, Ayush Gupta, Mohammadreza Heydary, Ekaterina Ignasheva, Ram Iyengar, Grant Jensen, Alex Kanaukou, Prianka Liz Kariat, Alan Kelly, Kathleen Kenealy, Ho Ko, Sachin Kotwani, Andrei Kulik, Yi-Chun Kuo, Khanh LeViet, Yang Lu, Lalit Singh Manral, Tyler Mullen, Karthik Raveendran, Raman Sarokin, Sebastian Schmidt, Kris Tonthat, Lu Wang, Zoe Wang, Tris Warkentin, Geng Yan, Tenghui Zhu, and the Gemma group.

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