Graphics Cards Presentation

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2 Δεκ 2013 (πριν από 3 χρόνια και 8 μήνες)

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Graphics Cards

Presentation by David Fong

What are graphics cards used for?


Animation


Gaming


both PC and console


Design/Drafting


Special effects creation/editing


Medical Instruments


And other purposes where fast rendering and
high resolutions are needed



History


Over the years, more colors, higher resolution, faster bus interfaces, and more
memory.

History


Monochrome Display Adapter (MDA) was the
first video card created in 1981


displays green
text on black screen


Video Graphics Array (VGA) = very popular
and was the standard in almost every PC up
until recently


First 3d video cards were released in 1995 and
they used SVGA; learned to create 3d effects

Monochrome Monitor


Components


Graphics Processing Unit (GPU): perform calculations
for rendering and figure out what to do with each pixel


Video Memory: storing images and information about
each pixel


Output: Common outputs include Video Graphics
Array (VGA) for CRT monitors, Digital Visual
Interface (DVI) for flat panel displays, and Video
-
in
-
video
-
out (ViVo) for television and video cameras

Components


Heat sink and Fan: used to cool the GPU, just like the
CPU of a computer having the same cooling
instruments


Motherboards: PCI before AGP


Motherboards: Accelerated Graphics Port (AGP)
compatible popular decade ago; Peripheral Component
Interconnect Express (PCI
-
E) gaining popularity


BIOS chip that stores settings, information about each
component of the graphics cards, and can be altered for
over
-
clocking

Picture of Graphics Card

How graphics cards work?


Take data from CPU and figure out what to do
with each pixel to create image


Create wire frame using vectors


Fill remaining pixels with color, lighting, and
texture


The filling will consider viewpoint


For games and video, the graphics cards has to
do the above steps for 30 frames per second

How graphics cards work?


In greater detail:


GPU creates image, stores image with location and
color of each pixel in memory


Memory also holds completed images until it’s time
to display them (frame buffer)


Digital
-
to
-
analog converter (DAC) is connected to
memory and translates image into analog signals that
is sent through monitor cable and the image is
displayed on monitor

Wire image


Draw 12 lines for cube, then fill in


A curve is created by many short lines

3d Image Development

3d effect: Mip
-
Mapping


Pre
-
calculated images of target image


Target image, may have several copies which is
¼ the size of previous image


Makes rendering faster when the output is
moving toward and further away from a target
image

3d effect: Z
-
buffering


Each pixel is part of a 2d coordinate (x
-
y
coordinates)


Depth is z
-
coordinate


When a new object that is rendered wants to
take a pixel, Z
-
buffering checks which pixel is
closer to the observer, the old pixel or the new
pixel based on the z
-
coordinate


If new pixel is closer, the new pixel is buffered
and replaces old pixel


3d effect: Anti
-
aliasing


When trying to represent high resolutions signal
at lower resolutions.


Smoothes out edges to the human eye by
blending of colors

Anti
-
aliasing

Anti
-
aliasing

Anti
-
aliasing

Anti
-
Aliasing

Anti
-
Aliasing

Extra Features


ATI and nVidia added enhancements to their
GPUs including:


Anti
-
aliasing which makes smoother edges for 3d
objects


Anisotropic filtering: creating crisper images


Dual
-
monitor support which can increase
productivity


TV
-
tuner

Do you need a graphics card?


If you only surf the web, watch streaming
videos, chat, or word processing, the integrated
graphics processor on your motherboard is
enough.


If you play games or work with 3d graphics,
then a graphics card is recommended.


How to judge quality of graphics
card?


Most of the time, you can judge the quality of a
graphics card by the processor speed and how much
memory the card has.


There are some sites that do benchmark tests
(www.tomshardware.com) for comparable cards by
running graphics intensive games or environments and
measuring the frame rate (frames per second)


Higher the frames per second, the smoother the
transitions for frames in games and video

Manufacturers


Intel: develop IGPs (integrated graphics processors)


AMD (acquired ATI) develop GPUs


Nvidia also develop GPUs


Different manufacturers take GPUs and other
components to assemble video cards; thus creating
slight variations of video cards with same GPUs


Video cards are marketed with GPU manufacturer’s
brand name


Most popular video brands are the Radeon of ATI and
GeForce of Nvidia


IGPs vs Graphic Cards


About 90% of computers use IGPs


IGPs use the memory in the system instead of
having dedicated video memory like Graphics
Cards


IGPs are way cheaper than Graphics Cards


Performance always favors Graphics Cards


Almost impossible to play high end games on
IGPs


How much video memory you need?


Depends on resolution and bits per pixel (how
many colors possible for pixel)


32bpp = 2^32 = 4,294,967,296 colors


Minimum memory = Resolution x bpp


Example: 1024 x 768 x 32 bits per pixel


25,165,824 bits / (8 bits per byte)


3,145,728 bytes


So need a little bit more than 3 MB of memory

Future


Because of growing processor speeds, there may be a
need to develop a faster way for the CPU to transfer
bits to the GPU (like how AGP was needed a decade
ago, and PCI
-
E few years ago)


With greater GPU speeds, comes greater demand for
power (a simple PCI
-
E connection is not enough to
power a high quality graphics cards these days, most
likely needs additional sockets to be connected for
power)


The growth in processor speed and memory will create
higher fps at greater resolutions

Twix


How to calculate the minimum amount of video
memory you need?


Twix


What was the most popular bus interface before
PCI
-
E?

Twix


How do most benchmark tests measure the
performance of a graphics card?

Sources


Howstuffworks.com


Wikipedia.org


Encarta.msn.com


Brighthub.com


Pcwize.com