Explore everything about GPU from scratch.
What is GPU?
GPU is a specialized processor designed to handle computationally intensive tasks related to graphics rendering, image processing, and video encoding/decoding. Unlike a CPU (Central Processing Unit), which is designed for general-purpose computing. A GPU is optimized for parallel processing to perform thousands of calculations simultaneously.
How does GPU work?
The GPU's primary function is to render 2D and 3D graphics. This is essential for smooth gameplay, user interface animations, and video playback. It handles complex graphics operations such as texture mapping, shading, and lighting calculations, offloading these tasks from the CPU and delivering high-quality visuals.
GPUs found in smartphones are typically based on either the ARM Mali or Qualcomm Adreno architectures with a few manufacturers like Apple and Samsung developing their own custom GPU designs. These GPUs leverage advanced technologies such as unified shaders, which combine vertex and pixel shaders into a single programmable unit improving efficiency and performance.
One of the key features of a GPU is its ability to support various graphics APIs (Application Programming Interfaces) such as OpenGL ES, Vulkan, and, more recently, the low-overhead graphics APIs like Metal (for Apple devices) and Android GPU Compute. These APIs provide a standardized way for developers to access the GPU's capabilities and create visually stunning applications.
GPUs in smartphones also play a crucial role in machine learning and artificial intelligence applications. With their parallel processing capabilities, GPUs can accelerate the training and inference of neural networks for features like real-time object detection, augmented reality (AR), and computational photography.
The technology used in the manufacturing of smartphone GPUs is highly advanced and constantly evolving. These GPUs are typically fabricated using cutting-edge process nodes (e.g., 7nm, 5nm, or even smaller) and leverage advanced semiconductor materials and transistor architectures. This permits higher transistor densities, improved performance, and better power efficiency.
GPU manufacturers use various optimization techniques such as instruction-level parallelism, advanced caching mechanisms, and specialized memory architectures, to maximize performance and efficiency within the constraints of a mobile device.
Main features of GPU.
Programmable Shaders: Shaders are small programs that run on the GPU and handle various aspects of the rendering process such as vertex transformations, texture mapping, and pixel shading. Programmable shaders help developers to create complex visual effects and optimize performance.
Hardware Tessellation: This feature allows the GPU to dynamically generate and render detailed 3D models with high polygon counts in smoother and more realistic graphics.
Hardware-accelerated Video Decoding/Encoding: Many GPUs include dedicated hardware units for decoding and encoding various video formats offloading this computationally intensive task from the CPU and improving battery life.
Compute Capabilities: Modern GPUs support general-purpose computing to leverage their parallel processing power for tasks beyond graphics rendering such as physics simulations, computational photography, and machine learning.
Power Efficiency: Smartphone GPUs are designed with power efficiency in mind incorporating technologies like dynamic voltage and frequency scaling, which adjust the GPU's performance based on workload optimizing battery life.
Display Output: GPUs are responsible for rendering the final image and sending it to the display panel, often supporting various display technologies like OLED, LCD, and high-resolution displays.
Graphics Rendering: the GPU's primary function is to render images and graphics on the screen. It does this by processing complex mathematical calculations and transforming them into pixels, which are then displayed on the screen. Modern GPUs are highly optimized for parallel processing to handle large amounts of graphical data simultaneously.
Shader Cores: One of the defining features of modern GPUs is their shader cores. These are small processing units within the GPU responsible for executing specific tasks related to shading, texturing, and lighting in 3D graphics. The more shader cores a GPU has the better its performance in handling complex visual effects.
Texture Mapping Units (TMUs): TMUs are another critical component of the GPU that assists in applying textures to 3D models. They fetch texture data from the device's memory and apply it to the surfaces of objects in a scene enhancing their visual realism.
Memory Bandwidth: The GPU relies on fast access to memory to process graphical data efficiently. High memory bandwidth allows the GPU can quickly retrieve texture and shader data from the device's RAM.
API Support: GPUs in smartphones support various graphics APIs (Application Programming Interfaces) such as OpenGL ES, Vulkan, and DirectX. These APIs provide developers with standardized methods for interacting with the GPU to create visually stunning and immersive experiences on mobile devices.
Power Efficiency: With the increasing demand for high-performance graphics in smartphones, power efficiency has become a crucial consideration for GPU designers. Modern GPUs incorporate advanced power management techniques such as dynamic voltage and frequency scaling to optimize performance while minimizing power consumption and heat generation.
Manufacturing Technology: GPUs are typically manufactured using advanced semiconductor fabrication processes, such as FinFET or FD-SOI (Fully Depleted Silicon on Insulator), which help the production of smaller more power-efficient chips. These technologies allow GPU manufacturers to pack more transistors onto a single chip increasing computational power while reducing energy consumption.