Technical data

Image Quality
Image quality is a topic that would easily merit its
own article, if not a book in its own right.What I
mean here is the quality of the rendered 3D scene
as it appears on the player’s screen.This whole dis-
cussion was originally caused by the tricks and
tweaks that graphics card makers have begun to
build into their drivers.Their goal is to get the
most perform-
ance out of
their cards, and
to this end,
sometimes cer-
tain calcula-
tions are either
skipped or sim-
plified. In prin-
ciple, this is
possible in a lot of
places without the
player being forced
to accept reduced
image quality.
Unfortunately, the
chipmakers tend to
do a bit too much
tweaking, especially
to win performance
comparisons.The
result is often visibly reduced image quality, notice-
able at least to experienced users. Casual gamers, on
the other hand, may often not even notice any-
thing. In our article (http://graphics.tomshard-
ware.com/graphic/20040603/index.html) we took
a look at a number of optimizations used by the
graphics chip companies, and explained how they
work and what effect they have on image quality
and 3D performance.
Here is an image quality comparison taken from
the game FarCry using older drivers. In this driver,
NVIDIA replaced some of the game’s own shaders
with highly optimized ones.The result is visibly
reduced image quality on the one hand, but
improved performance on the other.
Meanwhile, the chipmakers have learned that
many users don’t necessarily want such optimiza-
tions, especially if they are forced upon them.
Anyone who pays $500 (or more) for a graphics
card understandably expects the highest possible
image quality.This is especially so considering that
such optimizations are not really that essential --
the enthusiast cards are now more than fast enough
to handle the highest quality settings. In response,
NVIDIA and ATI now allow for most of these
optimizations to be switched off in their most
recent drivers.
Another reason for reduced image quality can be
the use of reduced floating-point precision in
DirectX 9 games.A good example of this is the
game FarCry. NVIDIA’s GeForce FX cards render
most of the shaders using only 16-bit precision,
which leads to pronounced visual artifacts (see also:
http://graphics.tomshardware.com/g
raphic/20040414/geforce_6800-
46.html).
While NVIDIA has
addressed these quality issues with
newer drivers, the result is that the
frame rates have taken a nosedive
as a result
(http://graphics.
tomshardware.com/
graphic/20041004/
vga_charts-08.html).
NVIDIA was only able to over-
come this performance handicap
in DirectX 9 games with the new
GeForce 6xxx line.
Since the image quality pro d u c e d
by a card can change with literally
eve r y driver re l e a s e , we recommend staying inform e d
by reading the rev i ews of new card generations, as we
also regularly test the image quality in these art i c l e s .
#4 Budget (Card Overview)
E
ach graphics chip maker develops products for
every price category. Pictured here is
NVIDIA’s roadmap from the year 2003.
Cards can generally be categorized into three
large groups, each of which can once again be sub-
divided into two subgroups.The two big graphics
chip companies, ATI and NVIDIA, offer different
chips for each of the various price brackets. Note
that the boundaries between the categories tend to
blur quite a bit, however, due to price fluctuations
in the market.
The three main price groups are the entry-level
THG Graphics Card
Buyers Guide
9