XXXXXXX 2005 MA XIMUMPC 00
BUYERS GUIDE
NOVEMBER 2005 MA XIMUMPC 25
Your PC will have one of two types of videocard bus inter-
face—AGP (Accelerated Graphics Port, shown in the top
photo) or PCI Express (shown
in the bottom photo). Make
sure the videocard you buy is
compatible with your moth-
erboard: You can’t plug a PCI
Express card into an AGP slot,
and vice versa. PCI Express is
considerably faster than AGP,
offering maximum bandwidth
of 8GB/s, compared with just
2.1GB/s for AGP.
If your motherboard doesn’t
have PCI Express slots, your
videocard pickins will grow
increasingly slim. Neither ATI
nor nVidia plan to support the
older standard with their newest
GPUs. And both companies’
dual-GPU solutions—ATI’s
CrossFire and nVidia’s SLI—
require PCI Express, as well.
If you want the best videocard
performance and you’re still
scraping by with AGP, upgrade
your motherboard before you
spend money on a new card.BUS INTERFACE
Typically, videocards have two or three different types of
ports you can use to connect your display: DVI, VGA, or
TV-out. DVI is used to connect a digital display, such as
an LCD, or it can drive an analog monitor via an adapter.
VGA connects an analog computer display, such as a CRT.
TV-out outputs an S-Video or RCA composite analog video
signal that’s compatible with consumer televisions, VCRs,
and the like.
Most videocards have at least one DVI port and one VGA
port. High-end cards offer dual DVI ports, so you can run
two flat-panel displays in digital mode, or any combination
of analog and DVI displays with the appropriate adapters.
Cards that support TV-out usually include a breakout cable
with connectors for composite, S-Video, and—if the card
supports high-definition TV—component video. Better cards
will have a VIVO (video-in/video-out) port instead of TV-out.
This type of port can both input and output a TV-compatible
analog video signal. Videocards with VIVO ports can digitize
analog video in real time, which makes them suitable for
basic nonlinear video editing.DISPLAY INTERFACE
Every component inside your PC gener-
ates some degree of heat, and video-
cards produce more than most. A simple
heatsink isn’t sufficient to keep a high-
clocked GPU and memory cool, so man-
ufacturers now mount fans on the circuit
boards. ATI’s current top-end GPU, the
Radeon X850 XT Platinum Edition, gets
so hot that it requires a large cooling fanthat consumes two slots. nVidia’s refer-
ence design for its newest GeForce 7800
GTX, which boasts a 110-nanometer pro-
cess and sophisticated power-manage-
ment firmware, needs only a single-slot
cooler. If you have a cramped case, or
need to use all of your expansion slots,
you should look for a card that occupies
only one slot.COOLING SYSTEM
The amount of memory on the
videocard helps determine the
maximum resolution the card is
capable of displaying. Budget vid-
eocards will have at least 128MB of
DDR (double data-rate) RAM, but
256MB is the current sweet spot.
DDR2 and GDDR RAM are capable
of higher clock speeds than DDR
RAM. GDDR RAM was designed
specifically for 3D applications: It
requires less electrical power and
produces less heat than other types
of RAM, and can run at even higher
clock speeds.MEMORY
The wider the connection
between the videocard’s
GPU and its memory, the
faster the GPU can process
data. Budget videocards typ-
ically have a 128-bit interface
to memory, while higher-end
cards usually have a 256-bit
interface. Usually it’s bet-
ter to have slower-clocked
memory on a wider interface
than higher-clocked memory
on a narrow interface.MEMORY
Many videocard manufacturers offer “free” INTERFACE
software—and sometimes hardware—bun-
dles with their boards in an effort to differ-
entiate their products from the competition.
Shop around and you’ll soon discover that
the bundle is nearly always either a game,
application, or gadget that you already
own; an outdated version of a product; or
something that you had previously decided
you didn’t want, need, or care much about.
It’s always reasonable to pay a little more
for added performance, but most bundles
are merely marketing gimmicks designed to
lure the gullible. Benchmark results matter;
bundles don’t.SOFTWARE BUNDLE
VGA Video DVI