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The
Video Card
The
video, or ‘graphics’ card, as it is also known, is
responsible for collecting and converting the data
from your computer software into a usable signal for
the monitor. How fast and how accurately this process
happens, depends on several important factors.
One
important factor in the performance of the video card
is the connection slot that the card occupies on the
motherboard. There are 4 types of video card slots:
ISA, PCI, AGP, and PCI-Express. The outdated ISA slot
is no longer used. The PCI slot is used by older video
cards, which is fine for older software, but gives
limited performance. The AGP slot is a much faster
alternative, giving the video card direct access to
the system processor and memory, thus increasing the
flow of data. Current cards now use a newer type of
slot, called PCI-Express, which increases the flow of
video data dramatically.
Video
cards process a tremendous amount of data. Just typing
the letter ‘A’ means the video card must make
several different code calculations before the ‘A’
is sent to the monitor. The amount of data is
compounded tremendously when a moving image, as is
common in games, is sent to the monitor. Every frame,
with its size, colours, location, and refresh rate
must be all calculated, coded, and sent to the monitor
at the standard video rate of 30 frames per second. To
do this massive amount of work, most video cards have
their own processor and memory. This takes the load
off the main system processor and memory, leaving them
free to work other parts of the computer. The faster
the video card processor, and the more memory the card
has, the quicker it will do its job and give a better,
more life-like display on the screen.
Most
video cards are capable of coding their data in as
many as 16,700,000 different colours. This is called
24-bit or True Colour. However, often your video card
is set to run many less colours than this. Most cards
are set to run at 16-bit, or 65,536 different colours.
This is called High Colour. You may however have
noticed on your screen that the picture appears to be
grainy or splotched, as if not all the detail is
there. This is usually because the video card is set
to only 8-bit, or 256 colours. This means only 256
different colours are available for your video card to
use. The lowest setting your video card will use is 16
colours. This setting is mostly used for
troubleshooting your PC.
Another
factor in determining how your screen appears, is the
refresh rate. You may be surprised to learn that the
picture you see on your monitor is not one solid
image, but it is actually being re-drawn many times a
second. This number of times is called the refresh
rate. The rate is determined by your video card, the
most common being 60 times per second. This can be
increased to as much as 100 times per second.
If
you would like more information, please call us on
0419 790 071, or email us at info@mcsyarraman.com.au,
or visit our site.
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