graphicsprocessingunit

GRAPHICS PROCESSING

UNIT(GPU)

BY

AMAL RAJ.R

ELECTRONICS

INTRODUCTION

What is GPU?

• It is a processor optimized for 2D/3D graphics, video,

visual computing, and display.

• It is highly parallel, highly multithreaded

multiprocessor optimized for visual computing.

• Its uses parallel archetecture.

It is also called

Visual

processing unit

• It serves as both a programmable graphics processor

and a scalable parallel computing platform.

CPU VERSUS GPU

•

A SIMPLE WAY TO UNDERSTAND THE DIFFERENCE

BETWEEN A CPU ANDGPU IS TO COMPARE HOW

THEY PROCESS TASKS. A CPU CONSISTS OF A FEW

CORES OPTIMIZED FOR SEQUENTIAL SERIAL

PROCESSING WHILE A GPU HAS A MASSIVELY

PARALLEL ARCHITECTURE CONSISTS OF THOUSANDS

OF SMALLER, MORE EFFICIENT CORES DESIGNED FOR

HANDLING MULTIPLE TASKS SIMULTANEOUSLY

•

GPUS HAVE THOUSANDS OF CORES TO

GPU vs CPU

• A GPU is tailored for highly

parallel

operation while a CPU executes programs

serially

• For this reason, GPUs have many parallel execution units and higher transistor counts, while CPUs have few execution units and higher clockspeeds

• GPUs have much

deeper pipelines

(several thousand stages vs 10-20 for CPUs)

COMPONENTS OF A GPU

*

MOTHERBOARD

*

GRAPHICS PROCESSOR

* MEMORY

The images you see on your monitor are made of tiny

dots called

pixels

. At most common resolution

settings, a screen displays

over a million pixels

, and the

computer has to decide what to do with every one in

order to create an

image

. To do this, it needs a

translator something to take

binary data

from the CPU

and turn it into a picture you can see. Unless a

computer has graphics capability built into the

motherboard, that translation takes place on the

graphics card

The CPU sends information about the image to the graphics card. The graphics card decides how to use the pixels on the screen to create the image. It then sends that information to the monitor through a cable

To make a

3Dimage

,the graphics card first creates a wire frame out of straight lines. Then, it

rasterizes

the image (fills in the remaining pixels). It also adds

lighting,

texture and color.

For fastpaced games,the computer has to go through this process about sixty times per second. Without a graphics card to perform the necessary calculations, the workload would be too much for the computer to handle.

The graphics card accomplishes this task

using four main components:

A motherboard

connection for data and

power

A processor

to decide what to do with each

pixel on the screen

GRAPHICS PROCESSOR

A graphics card's processor, called a graphics processing unit (GPU), is similar to a computer's CPU. A GPU is designed specifically for performing the

complex mathematical and

geometric calculations

that are necessary for graphics rendering. Some of the fastest GPUs have

more transistors

than the average CPU. A GPU produces a lot of heat, so it is usually located under a

heat sink

or a fan.

RAM

PCI Connection

Graphics cards connect to the computer through the motherboard. The motherboard supplies power to the card and lets it communicate with the CPU. PCI Express is the newest form of connection and provides the fastest transfer rates between the graphics card and the

A good overall measurement of a card's

performance

is its

frame rate

, measured in frames per second (FPS). The frame rate describes how many complete images the card can display per second. The human eye can process about 25 frames every second, but fast action games require a frame rate of at least 60 FPS to provide smooth animation and scrolling

The graphics card's hardware directly affects its speed. These are the hardware specifications that most affect the card's speed and the units in which they are measured:

GPU clock speed (MHz)

Size of the memory bus (bits)

Amount of available memory (MB) Memory clock rate (MHz)

The GPU pipeline

•

The GPU receives

geometry

information(mainly triangles in 3D)

from

the CPU as an input and provides a

picture

as

an output

•

Let’s see how that happens

Host Interface

• The host interface is the communication bridge between the CPU and the GPU

• It receives commands from the CPU and also pulls

geometry information

from system memory

• It outputs a stream of

vertices

in object space with all their associated information (normals, texture coordinates, per

vertex color etc)

Vertex Processing

*A vertex processing is a graphics processing function that maps

vertices onto the screen and

adds special effects

to

objects in a 3D environment.

• One of its purposes is to transform each vertex's 3D position

in virtual space to the 2D coordinate at which it appears on the screen.

• Vertex pipelines also eliminate unneeded geometry by

detecting parts of the scene that are hidden by other parts

and simply discarding those parts

Triangle setup

Rasterization

It is the process of determining which screenspace pixel

locations are covered by each triangle. Each triangle generates a primitive called a “fragment” at each screenspace pixel location that it covers.

Triangle Setup (cont)

• A fragment is generated if and only if its center is inside the triangle

host interface

vertex processing

triangle setup

pixel

processing

Fragment Processing Or Pixel processing

• Each fragment provided by triangle setup is fed into fragment processing as a set of attributes (position, normal, texcoord etc), which are used to compute the final color for this pixel

• The computations taking place here include

texture

mapping

and

math operations

Memory Interface

• Fragment colors provided by the previous stage are written to the framebuffer

• Before the final write occurs, some fragments are rejected by the zbuffer, stencil and alpha tests

• The final pixels are processed and are provided as picture

Diagram of a modern GPU

64bits to memory 64bits to memory 64bits to memory 64bits to memory

Input from CPU

Host interface Vertex processing Triangle setup Pixel processing

GPU MANUFACTURERS:

LATEST GPU TECHNLOGY

CUDA Parallel Computing

CUDA IS NVIDIA’S PARALLEL COMPUTING ARCHITECTURE THAT ENABLES DRAMATIC INCREASES IN COMPUTING PERFORMANCE BY HARNESSING THE POWER OF THE GPU (GRAPHICS PROCESSING UNIT).

PHYSX TECHNOLOGY

NVIDIA PHYSX TECHNOLOGY HELPS GAMES PLAY BETTER AND FEEL BETTER BY MAKING INTERACTION WITH ENVIRONMENTS AND

CHARACTERS FAR MORE REALISTIC THAN EVER BEFORE. BY MAKING BEHAVIOR MORE REALISTIC, THE GRAPHICS LOOK AND “FEEL”BETTER

NVIDIA 3D Vision Technology

LATEST GPU AVAILABLE IN MARKET

NVIDIA GEFORCE Gtx 980 Ti

It supports: CUDA

3D Vision PhysX 4k

GTX 980 TI Memory Specs:

Memory Clock :1753 MHZ Memory size:6GB

AMD Radeon R9 290X

Memory Clock :1250 MHZ Memory size:4GB