MMTA Graphics 1

1
MMTA Graphics 1

• Original PC
• Simple monochrome character based display
• - MDA
• See MSDOS application
• Storage size was not a problem
• Requirement 80 characters25 lines2 bytes
• 4000 bytes

2
MMTA Graphics 2

• Colour graphics 3202002 bits (4 colours)
• Bit-mapped display can set any bit
• Connected to a TV or
• dedicated 4-bit "RBGI" interface CRT monitor
• Memory size ?
• Much more than character based screen

3
MMTA Graphics 3

• More modern VGA adapter
• Card Resolution Colours Memory
• VGA 640480 256 256KB
• SVGA 800600 256 512KB
• XGA 1024768 65,536 2MB
• Wiki CGA

4
MMTA Graphics 4

• Video memory size is not the main problem
• Drawing takes significant CPU time.
• e.g Blue circle
• Better solution use a graphics processor
• Display adapter incorporates
• graphics memory and
• graphics coprocessor

5
MMTA Graphics 5

• Modern systems
• CPU and memory linked to graphics via AGP
  Accelerated Graphics Port or now PCIe

CPU
graphics coprocessor
Video Image Frame Buffer
video output circuit
Monitor interface
6
MMTA Graphics 6

• Graphics card now
• Self contained subsystem
• Gets image data either
• as display list data or
• as pixel data from the cpu
• State the features of a modern graphics card

7
MMTA Graphics 7

• Not just for games
• Important for graphic designers and 3D animators
• Fast rendering to make work look more realistic

8
MMTA Graphics 8

• Graphics processing unit (GPU)
• Processor optimised for 3D graphics and rendering
  
• Translate a 3D image (vertices and lines) into a
  2D image formed by pixels
• Video BIOS
• Governs card's operations
• Provides instructions for main CPU interface

9
MMTA Graphics 9

• Video memory
• No longer use CPU memory Video RAM
• Accessed by the GPU and the display circuitry
  high speed, multiport RAM
• Type Clock rate (MHz) Bandwidth(GB/s)
• DDR 166 950 1.2 - 30.4
• DDR2 533 1000 8.5 16
• GDDR3 700 1800 5.6 - 54.4
• GDDR4 1600 2400 64 - 156.6
• GDDR5 3000 3800 130 - 230
• VRAM may also have Z-buffer
• manages depth in 3D graphics shading

10
MMTA Graphics 10

• DDR2 Double data rate 2
• Technology to get twice bandwidth from RAM
• GDDR3 Graphics DDR
• Reduced heat requirements
• NVidia GeForce
• Xbox 360
• Wii
• GDDR4 5 further enhancements / speed

11
MMTA Graphics 11

• RAMDAC
• Digital to Analogue converter to displays
• CRT displays gt 60Hz to minimize flicker
• LCD displays flicker is not a problem
• Now part of GPU
• LCD and Plasma displays are digital.
• Outputs
• VIVO, DVI, VGA

12
MMTA Graphics 12

• Others
• Motherboard interface - PCIe
• Cooling heat sink, fan, water
• Power demand largest in computer
• Via PCI connection 75W max
• Direct power supply connection
• Interfaces -

13
MMTA Graphics 13

• Others
• Interfaces -

14
MMTA Graphics 14

• Additional functions
• Video capture,
• TV tuner adapter,
• MPEG-2 and MPEG-4 decoding,
• FireWire,
• light pen,
• TV output,
• Multiple monitors.