CSE 581: Module 2 - Hardware

Raghu Machiraju

Slides: Courtesy - Prof. Huamin Wang, CSE, OSU

Architecture

CPU

Memory

Power

Hard drive

DVD ROM

Keyboard and mouseGraphics card

Raster Graphics Systems

Raster: Images are represented by an array of picture elements (pixels).

1 bit: black & white8 bits: 256 levels of gray32 bits: 16 million colors (true color)

Frame Buffer

Screen resolution Pixel format Refresh rate

Size of Frame Buffer

• For example, the screen is 1960×1080 with 24 bits per pixel, how big is the frame buffer?

• Frame buffer may store other information, such as depth values.

Number of pixels × Bits per pixelScreen resolution Pixel format

1960×1080×24=51M bits = 6M bytes

A Prototype Graphics System

System bus (motherboard)

CPU Memory

Video controller

Frame buffer Frame buffer in main memory?

An Early Graphics System

System bus (motherboard)

CPU Memory

Video controller

Graphics card/video card/display card

Graphics memory

Graphics memory: on-board frame buffer for faster access

An Early Graphics System

System bus (motherboard)

CPU Memory

Video controller

Graphics card

Graphics memory

A processor dedicated for graphics processing Graphics processor (GPU)

Companies Building Graphics Cards

Comparison

(Flops: Floating-point operations)

Evaluation

Graphics Pipeline: Software

Graphics Pipeline: Hardware

Geometry stage Rasterization stage

Graphics Bus Interface: Peripheral Component Interconnect (PCI)

System bus (motherboard)

CPU Memory

Video controller

Graphics card

Graphics memoryGraphics processor (GPU)

PCI bus

Other peripherals:wireless card,sound card,

…

133MB/s

Problems with PCI

• PCI bus becomes a bottleneck!– Shared with other devices.– Lots of data from main memory to graphics

memory: textures, geometry…– Example: 2M triangles, 90 bytes each =>

180 MB > 133 MB (PCI bandwidth)

Graphics Bus Interface:Accelerated Graphics Port (AGP)

System bus (motherboard)

CPU Memory

Video controller

Graphics card

Graphics memoryGraphics processor (GPU)

PCI bus

Other peripherals:wireless card,sound card,

…

AGP 1.1: 533 MB/sAGP 3.0: 2133 MB/s

AGP bus132 MB/s

Features of AGP

• No local bus congestion.• Faster data transfer (20 times faster than PCI).• More geometry can be transferred.• Direct execution of many operations from the

man memory.

Graphics Bus Interface: Peripheral Component Interconnect Express (PCI-e)

System bus (motherboard)

CPU Memory

Video controller

Graphics card

Graphics memoryGraphics processor (GPU)

(Shared, parallel) PCI-e bus

Other peripherals:wireless card,sound card,

…

3GB/s

Readings & Labs

Textbook: Chapter 1 & 2