The document discusses graphics processing units (GPUs). It begins with an introduction and definition of GPUs as processors designed specifically for processing 3D graphics. It then covers the components of a GPU and compares GPU and CPU architectures. Specifically, it notes that GPUs have many parallel execution units while CPUs have few, and that GPUs have significantly faster memory interfaces than CPUs. The document concludes by noting that GPU development is ongoing and faster GPUs can be expected in the future.

1. Submitted By:
MANISHA CHAUDHARY
Seminar
On
Graphics Processing
Unit
LUCKNOW INSTITUTE OF TECHNOLOGY,
LUCKNOW
Submitted to :
Ms. ARTI SINGH

2. INTRODUCTION
DEFINITION
COMPONENTS OF GPU
COMPARISON WITH CPU
ARCHITECTURE
CONCLUSION
Content

3. Introduction
 A Graphics Processing Unit (GPU) is a microprocessor that
has been designed specifically for the processing of 3D
graphics.
 The processor is built with integrated transform, lighting,
triangle setup/clipping, and rendering engines, capable of
handling millions of math-intensive processes per second.
 GPUs form the heart of modern graphics cards, relieving
the CPU (central processing units) of much of the graphics
processing load.

4. Why GPU?
 To provide a separate dedicated graphics
resources including a graphics processor and
memory.
 To relieve some of the burden of the main system
resources, namely the Central Processing Unit,
Main Memory, and the System Bus, which would
otherwise get saturated with graphical operations
and I/O requests.

5. What is a GPU?
 A Graphics Processing Unit or GPU (also
occasionally called Visual Processing Unit or
VPU) is a dedicated processor efficient at
manipulating and displaying computer graphics .
 Like the CPU (Central Processing Unit), it is a
single-chip processor.

6. HOWEVER,
The abstract goal of a GPU, is to enable a
representation of a 3D world as realistically as
possible. So these GPUs are designed to provide
additional computational power that is customized
specifically to perform these 3D tasks.

7. 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 , while CPUs have few execution
units .
 GPUs have singificantly faster and more
advanced memory interfaces as they need to shift
around a lot more data than CPUs.
 GPUs have much deeper pipelines (several
thousand stages vs 10-20 for CPUs).

8. BRIEF HISTORY
 First-Generation GPUs
 Up to 1998; Nvidia’s TNT2, ATi’s Rage, and 3dfx’s Voodoo3;DX6 feature set.
 Second-Generation GPUs
 1999 -2000; Nvidia’s GeForce256 and GeForce2, ATi’s Radeon7500, and S3’s
Savage3D; T&L; OpenGL and DX7;Configurable.
 Third-Generation GPUs
 2001; GeForce3/4Ti, Radeon8500, MS’s Xbox; OpenGL ARB, DX7/8; Vertex
Programmability + ASM
 Fourth-Generation GPUs
 2002 onwards; GeForce FX family, Radeon 9700; OpenGL+extensions, DX9;
Vertex/Pixel Programability + HLSL; 0.13μ Process, 125M T/C, 200M T/S.
 Fifth-Generation GPUs
- GeForce 8X:DirectX10.

9. COMPONENTS OF GPU
 Graphics Processor
 Graphics co-processor
 Graphics accelerator
 Frame buffer
 Memory
 Graphics BIOS
 Digital-to-Analog Converter (DAC)
 Display Connector
 Computer (Bus) Connector

10. GPU Architecture
How many processing units?
 Lots.
How many ALUs?
 Hundreds.
Do you need a cache?
 Sort of.
What kind of memory?
 very fast.

11. The difference…….
Without GPU With GPU

12. The GPU pipeline
 The GPU receives geometry information from the
CPU as an input and provides a picture as an
output
 Let’s see how that happens…
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

13. 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 (texture
coordinates, per vertex color etc) .
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

14. Vertex Processing
 The vertex processing stage receives vertices from the
host interface in object space and outputs them in screen
space
 This may be a simple linear transformation, or a complex
operation involving morphing effects
 No new vertices are created in this stage, and no vertices
are discarded (input/output has 1:1 mapping)
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

15. Triangle setup
In this stage geometry information becomes
raster information (screen space geometry is the
input, pixels are the output)
Prior to rasterization, triangles that are
backfacing or are located outside the viewing
frustrum are rejected
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

16. Triangle Setup (cont…..)
A pixel is generated if and only if its center is inside
the triangle
Every pixel generated has its attributes computed to
be the perspective correct interpolation of the three
vertices that make up the triangle

17. Pixel Processing
Each pixel provided by triangle setup is fed into
pixel processing as a set of attributes which are
used to compute the final color for this pixel
The computations taking place here include
texture mapping and math operations
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

18. Memory Interface
 Pixel colors provided by the previous stage are written to
the framebuffer
 Used to be the biggest bottleneck before pixel processing
took over
 Before the final write occurs, some pixels are rejected by
the zbuffer .On modern GPUs z is compressed to reduce
framebuffer bandwidth (but not size).
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

19. Programmability in GPU pipeline
 In current state of the art GPUs, vertex and pixel
processing are now programmable
 The programmer can write programs that are executed
for every vertex as well as for every pixel
 This allows fully customizable geometry and shading
effects that go well beyond the generic look and feel of
older 3D applications
host
interface
vertex
processing
triangle
setup
pixel
processing
memory
interface

20. Conclusion
 Graphics Processing Unit is not a wonder that this
piece of hardware is often referred to as an exotic
product as far as computer peripherals are
concerned.
 By observing the current pace at which work is going
on in developing GPUs we can surely come to a
conclusion that we will be able to see better and
faster GPUs in the near future.

21. Reference
 www.google.com
 www.wikipedia.com
 www.studymafia.org

22. Thanks