PC Hardware A Beginner’s Guide

(^238) PC Hardware: A Beginner’s Guide
Video Processors
Video cards all have some level of processing capability. The onboard processor gener-
ates some or all of the image to be displayed by the monitor. How much of the video load
is carried by the video card’s processor and chipset depends on the age of a video card
and, typically, how much it cost.
Video cards use three different technologies to generate the image for the monitor:

Frame buffer Older cards use the frame buffer technology that focuses
on displaying one video frame at a time and leaving the CPU (the one
inside the PC) to create the graphic image to be displayed.
 Graphic acceleration The video cards that use this technology are called
(what else?) graphic accelerators. On this type of video card, the video processor
performs all of the routine and common tasks associated with generating
graphic images, and the CPU is used strictly for what needs to be done and
when. This type of video card processing is the most common in PCs.
 Graphics Processing Units (GPUs) On newer, high-end video cards, the
onboard processor and chipset have the complete responsibility for generating
all displayed graphics, which leaves the CPU free to do other tasks.
Video processors are divided into two categories:

2D This is normal everyday ordinary graphics, the kind used by most
standard applications, such as word processing and spreadsheets, and many
multimedia applications, such as PowerPoint and CorelDraw. In fact, this is
the minimum level of graphics on a PC.
 3D This is the graphics type used by games and 3D rendering and drawing
software. Unfortunately, 3D graphics and the processor commands used to
generate them are not standardized. As a result, some 3D programs and games
may not work with every video card.
Video Bus
Video cards use either the PCI or AGP bus architectures. The PCI bus is independent of
the processor, which makes for fast video. The AGP bus offers a higher bandwidth and
withit,higherframerates.IthasadirectlinetoRAM,whichallowsittobetterprepare3D
images and textures.
Video RAM
VideoRAM(VRAM)servestwopurposesonthevideocard:one,itactsasabufferbetween
the CPU and data bus and the monitor, and two, it is the work area used by the video
processor and chipset to perform the calculations used to formulate the graphic image
as an analog signal for the monitor.