Specifications

Upgrading or Replacing Your Video Card
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Note
With the rise in popularity of Linux, many graphics card and GPU vendors now provide downloadable Linux drivers. Be sure
to check compatibility carefully because some vendors customize drivers for different Linux distributions or might provide dri-
vers that work with only certain Linux kernels or XFree86 drivers.
Comparing Video Cards with the Same Chipset
Many manufacturers create a line of video cards with the same chipset to sell at different pricing points.
Why not save some dollars and get the cheapest model? Why not say “price is no object” and get the
most expensive one? When you’re faced with various cards in the “chipsetX” family, look for differ-
ences such as those shown in Table 15.21.
Table 15.21 Comparing Video Cards with the Same Features
Feature Effect on You
RAMDAC speed Most current high-end 3D GPUs integrate 400MHz RAMDACs to provide flicker-free res-
olutions beyond 1280×1024. However, less-expensive cards and older designs often
incorporate a slower RAMDAC, which reduces maximum and flicker-free resolutions. If
you use a 17'' or larger monitor, this could be an eye-straining problem.
Amount of RAM Although AGP video cards can use AGP memory (a section of main memory borrowed
for texturing), performing as much work as possible on the card’s own memory is still
faster. PCI cards must perform all functions within their own memory. Less expensive
cards in a chipset family often have lower amounts of memory onboard, and graphics
cards haven’t featured expandable memory for several years. Buy a card with enough
memory for your games or applications—today and tomorrow; at least 64MB or more
for business and 128MB or more for gaming, 3D graphics, and video-related work.
Memory type Virtually all video cards on the market today use SDRAM or its faster variants (SGRAM,
DDR SDRAM, DDR-II, or GDDR-3 SDRAM). Any of these provides you with high perfor-
mance in business applications, although DDR, DDR-II, or GDDR-3 SDRAM is preferable
when running high-resolution, high-quality 3D games faster.
Core clock speed Many suppliers adjust the recommended speed of graphics controllers in an effort to
provide users with maximum performance. Sometimes the supplier can choose to exceed
the rated specification of the graphics chip. Be cautious: Current controller chips are
large and can overheat. An overclocked device in an open system with great airflow
might work, or it might fail in a period of months from overstress of the circuitry. If you
have questions about the rated speed of a controller, check the chip supplier’s Web site.
Many reputable companies do use overclocked parts, but the best vendors supply large
heatsinks or powered fans to avoid overheating. Some vendors even provide on-card
temperature monitoring.
RAM Speed (ns rating) Just as faster system RAM improves overall computer performance, faster video card
RAM improves video card performance. Some high-performance 3D video cards now
use DDR SDRAM memory chips with a 2.8ns access time.
TV-out Once a rare feature, most mid-range and most high-end video cards now feature TV-out,
enabling you to display DVD movies or video games on a big-screen TV. Some of the
latest models have hardware-based MPEG-2 compression for higher video quality in less
disk space. Some of the latest video cards are now using a VIVOport to support either
RCA or S-video inputs on VCRs and TVs.
The speed of the RAMDAC is not the same as the core clock speed of a given graphics card. Even though most current
GPUs incorporate the RAMDAC in the GPU, the RAMDAC and the GPU core run at different speeds.
Chapter 15
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