Simple Science

Cutting edge science explained simply

# Computer Science # Performance

Enhancing LLM Speed with SparseInfer

SparseInfer improves large language models by boosting speed and reducing memory use.

Jiho Shin, Hoeseok Yang, Youngmin Yi

― 5 min read


SparseInfer Speeds Up SparseInfer Speeds Up LLMs speed for language models. SparseInfer cuts memory use and boosts
Table of Contents

In the tech world, large language models (LLMs) are the rock stars. They do everything from writing poetry to holding conversations. But just like every star needs a good stage, these models need a great way to work quickly. And here’s the kicker: they don’t always do that, especially when their fancy activation functions decide to take a nap. Let’s dig into the wild world of LLMs, Activation Sparsity, and how we can make things run a little smoother.

What’s Wrong with Current Models?

Modern LLMs often use a fancy activation function called SiLU. It sounds great, but it doesn’t really help our models be as fast as they could be. In short, SiLU isn’t sparking joy! Recent research says that switching to another function called ReLU can make things much better by letting more zeros pop up in the process. Zeros are like the quiet kids in class – they don’t take up much space and can help everything go faster.

The Pain of Prediction

Swapping out SiLU for ReLU is a clever move, but there’s still a catch: you need to predict where those zeros will be to take full advantage. This is where things get complicated. Right now, we have to train a separate model just to make these predictions, which takes time and resources. Plus, no one wants to have to buy a bigger suitcase (or Memory) just for a sidekick!

Enter SparseInfer: The New Hero

Now, let’s introduce our hero: SparseInfer. It’s like a trusty sidekick who doesn’t need any special training! This tool estimates which inputs will be zero based on something much simpler – just looking at the signs of the inputs and weights. Basically, it checks if they’re positive or negative, which is way easier than complicated math.

The Perks of SparseInfer

SparseInfer isn’t just a pretty face. It comes with a few nifty features. If it gets a prediction wrong, it has a backup plan. It can adjust how conservative it is about predictions, which means it can find a nice balance between speed and Accuracy. This way, it doesn’t go all-out and end up with silly mistakes.

The Results Are In

When SparseInfer comes into play, it can speed up the model significantly. In some tests, it sped up Inference by about 21% compared to other systems while only sacrificing a smidgen of accuracy – less than 1%. Imagine running a marathon a fifth faster while still crossing the finish line!

How Do We Use SparseInfer?

Let’s break it down. First, we want to avoid extra memory use, so SparseInfer packs up the sign bits instead of the whole input data. This is like carrying just your snacks instead of a whole picnic basket.

Then, it uses a simple lookup to check if the inputs will produce a zero when processed. Each time it checks, it uses teamwork from threads on the GPU to speed things up. It’s like a group of people lifting a heavy box – one person can do it, but it’s much easier when everyone pitches in!

The Importance of Sparsity

Activation sparsity means we can skip over parts of the input that don’t contribute to the final result. This is crucial because accessing memory takes time, and we don’t want our model to be stuck waiting. Instead, we can skip the boring parts and focus on the exciting bits that actually matter!

Real-World Performance

Tests show that SparseInfer really delivers. When combined with existing tools, the total time taken for token generation went down significantly. In fact, it was much better than previous methods. The system even remembers how to be smart during different layers, using a special scale to balance speed and precision.

What About the Competition?

Other methods exist, but many rely on training during setup, which means they aren’t as flexible. SparseInfer stands out because it doesn’t need to go through a training phase, so it can adapt easily to different models. It’s like having a Swiss Army knife instead of just a single tool!

Memory Matters

One of the biggest advantages of SparseInfer is the amount of memory it saves. Other methods use a lot of brainpower and memory just to keep track of their predictions. SparseInfer, on the other hand, is like a minimalist who knows how to make the most of a small space. It only requires the essential bits to keep things working smoothly.

How It Works on the Ground

When we put SparseInfer to the test on different LLMs, it performed exceptionally well. The results were fast and reliable, allowing the models to run with less lag and lower memory consumption. On platforms like NVIDIA Jetson Orin, SparseInfer shined brightly, showing how efficient it could be in various scenarios.

Conclusion: The Bright Future of LLM Performance

The introduction of SparseInfer is a game changer for speeding up language models. By making effective use of prediction without needing complicated training, it opens doors to new possibilities. The combination of simplicity, speed, and lower overhead makes SparseInfer an appealing choice for anyone working with large language models.

So, as we continue to build smarter and faster models, let’s not forget to appreciate the little things like sparsity – the unsung hero helping us all move forward with ease!

Original Source

Title: SparseInfer: Training-free Prediction of Activation Sparsity for Fast LLM Inference

Abstract: Leveraging sparsity is crucial for optimizing large language model inference. however, modern LLMs employing SiLU as their activation function exhibit minimal activation sparsity. Recent research has proposed replacing SiLU with ReLU to induce significant activation sparsity and showed no downstream task accuracy degradation through fine tuning. However, taking full advantage of it required training a predictor to estimate this sparsity. In this paper, we introduce SparseInfer, a simple, light weight, and training free predictor for activation sparsity of ReLU field LLMs, in which activation sparsity is predicted by comparing only the sign bits of inputs and weights. To compensate for possible prediction inaccuracy, an adaptive tuning of the predictor's conservativeness is enabled, which can also serve as a control knob for optimizing LLM inference. The proposed method achieves approximately faster inference speed over the state of the art, with negligible accuracy loss of within 1%p.

Authors: Jiho Shin, Hoeseok Yang, Youngmin Yi

Last Update: 2024-11-19 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2411.12692

Source PDF: https://arxiv.org/pdf/2411.12692

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

More from authors

Similar Articles