With the GeForce 6800 Ultra,
NVIDIA is not only the first company to introduce GDDR3
equipped video cards and 16 pixel pipelines in a single
chip, but they've expanded the feature set of their GPUs to
fully support the relatively new Shader Model 3.0 as well.
The GeForce 6800 Ultra also has a new video engine
built-into the chip, a new anti-aliasing method, and
a beefed up version of NVIDIA's proprietary UltraShadow
Feature Spotlight: GeForce 6800 Ultra
Wider is Better | Più largamente è
CineFX 3.0 &
Shader Model 3.0:
Shader Model 3.0, which will be
available upon the release of DirectX 9.0c, basically builds
upon Shader Model 2.0 by increasing the maximum number of
Vertex and Pixel shader instructions that can be executed by
the GPU, and by raising the minimum level of shader
precision required to be compliant. The GeForce 6
Series can process an infinite number of pixel and vertex
shader instructions, which far exceeds the minimum
specification of 65,536. The GeForce 6 Series also has
support for Displacement mapping, Vertex Texture Fetch,
Pixel Shader Subroutines, Loops & Branches and Dynamic Flow
control. Support for these specifications make the
NV40 act more like a general purpose CPU, giving it the
ability to process instructions with more flexibility, which
in-turn gives developers more freedom when programming
TRADITIONAL NON SCALAR SHADER: ONE SHADER UNIT
GEFORCE 6 SERIES SHADER: WITH SECOND SHADER UNIT
The NVIDIA GeForce 6 Series also
has a new shader architecture that can double the number of
operations executed per clock cycle. Each of the
NV40's pipelines is now equipped with a second shading unit
(right). Traditional shaders (left) generally have a single
shading unit that can process up to 4 operations per pixel,
per clock cycle. By adding a second shading unit to
each pipeline the NV40 architecture delivers a twofold
increase in the number pixel operations that can be
processed per clock cycle. This "superscalar"
architecture, as NVIDIA calls it, is capable of up to four
instructions and eight operations per pixel, compared to
just two instructions and four operations in traditional
As games and
their underlying game engines get more complex, and have to use multiple
passes to render shadows from different light sources, the
need to process these shadows efficiently and quickly gets
increasingly more important. With the NV3x architecture, NVIDIA
introduced a proprietary technology called "UltraShadow"
that helps render complex shadows relatively quickly,
when compared to products without UltraShadow. NVIDIA
pointed to ID's upcoming game Doom 3 as one of the titles
that benefit greatly from their UltraShadow technology.
Back in June '03 we spoke to NVIDIA about this technology,
and asked how it gives them a performance advantage.
Basically, what UltraShadow does is cull shadows that fall
outside of a defined depth bound - if a shadow falls outside
of the boundary it is not rendered. This saves
processing time, and bandwidth, which ultimately increases
performance. With the GeForce 6800 Ultra, NVIDIA is
introducing UltraShadow II, and extension of their
technology which offers up tp 4x the performance
of the NV35.
3.0 & Rotated Grid Anti-aliasing:
NVIDIA has also revamped their
anti-aliasing engine with the GeForce 6 series. Cards
based on the NV3x used a four sub-pixel pattern that was
sampled in a two-by-two grid for each pixel. By
slightly rotating the grid into somewhat of a diamond shape
(similar to ATI's technique with the R3x0 architecture), the
resulting pattern of the four sub-pixels samples four values
for the horizontal and vertical sub-pixel positions. Using
samples that are essentially closer to the original pixel
results in more accurate colors at the polygon's edge.
The more accurate the colors, the less prominent jaggies
will appear in any given frame, which gives the overall
appearance of fewer jaggies in the scene.
(High Precision Dynamic Range):
The GeForce 6 Series is capable
of Studio-Quality, HDR (High Dynamic Range) rendering that
complies with the
format developed by Industrial Light & Magic (ILM) of
Lucasarts fame. ILM developed the OpenEXR format in
response to the demand for higher color fidelity in the
visual effects industry. In scenes with a very bright
light source in conjunction with extremely dark shadows,
there tends to be color banding in the dark portions of the
scene where the eye can better perceive slight differences
in color. NVIDIA's HPDR technology, which is
completely implemented in hardware, solves the problem of
high dynamic-range rendering by providing 16-bit floating point formats for storage, blending,
shading, texturing, and filtering during the light transport
phase. It also allows for the use of the sRGB format in the
tone mapping and color and gamma correction phases. For more
details, and in-depth explanations as to how HDR rendering
can affect an image, we strongly suggest checking out the
examples on the
website - as they say, a picture is worth a thousand
The NV40 also sports an on-chip
programmable video processor designed to improve the quality
and performance of video playback on the PC. NVIDIA's
on-chip video processor incorporates a high-quality adaptive
de-interlacing engine, along with better filtering and
scaling techniques, video de-blocking capabilities and an
integrated TV-encoder. The NV40's on-chip video
processor is also a complete HDTV solution as well, with the
ability to output HDTV streams in all of the popular formats
(720P, 1080i, 480P, CGMS). It also has PVR (Personal Video
Recorder) functionality, with hardware audio / video
synchronization, hardware MPEG 1 / 2 / 4 encoding and
decoding, and WMV9 decode acceleration.
Candy: NVIDIA's Demos
Showing Off the Features...
Sailing with NVIDIA, Dr.
Timbury and the lovely Nalu...
Upon the introduction of a new
architecture, NVIDIA always produces a few spectacular demos
designed to highlight the product's key features and
performance. At a recent press event we got to see all
three of the demos pictured above running live on the NV40,
and can say these screen captures do not do them justice.
The Sailing demo especially looked much better live and in motion.
It seems like these shots were taken with an early build of
the demo, as the one we were shown had the water splashing up on
the sides of the ship as it crashed into the waves.
The Dr. Timbury demo, was also fairly impressive. We
weren't too fond of the "cartoon-like" look, but when the
camera was positioned to show the NV40's HDR rendering at
work, the light bloomed around, and reflected off his shiny
head, in a very realistic fashion. Then we have Nalu.
Nalu is the mermaid cousin, of Dusk & Dawn - the NV3x
nymphs. Nalu has evolved to have much more realistic
looking skin, translucent shader effects for her "clothes"
and fins, and her hair is comprised of 10,000 individually
animated strands. The overall effect was very
realistic, especially when she spun and turned to show its
Drivers: Forceware v60.72
Without The Software, The Hardware is Useless
Tying all of the hardware's
features to the operating system is NVIDIA's Forceware drive
suite. Release 60 of the Forceware drivers add support
for the GeForce 6 series of products, as well as NVIDIA's
PCI Express products based on the NV3x architecture.
Unified Compiler performance has been improved approximately
10% - 35%, an optimized PS3.0 complier has been added, and
support for NV4x's video engine has been incorporated as
well. Release 60 also integrates all of the new
features first introduced with the Forceware 55 release,
like a built in pop-up blocker, application specific
profiles and auto overclocking (on supported products).
We've already covered these new features in more detail in a
previous article, so we don't spend too much time on them
here. But if you'd like to read up on them,
head on over to this page. Release 60 is
designated as beta at the moment, and should be ready for
public consumption at the end of May.