|  Articles | Asus Extreme N7800GT Review | Asus Extreme N7800GT Review | Asus Extreme N7800GT Review Published on September 21th, 2005
Introduction
Asus doesn’t really need any further introduction. Most people
out there know who Asus are and what they stand for. Those of you who
don’t know; Asus won 1171 awards in 2004 from the worlds most
respected IT media and organizations.
* Business Week ranked ASUS amongst its "InfoTech top 100" for the eighth straight year
* Toms Hardware Guide, the worlds largest IT website, selected ASUS
as the best maker of motherboards (4 consecutive years) and graphics
cards (two consecutive years)
* They took home the prestigious "National Award of Excellence"
presented by the Ministry of Economic Affairs and Germanys Industry
Forum (iF) Award for industrial design excellence
That says lot about Asus as a company, I have had the pleasure to own
many Asus products myself from mother boards to graphics cards to
CD/DVD drives and I was always very pleased with the excellent build
quality. Thanks to these previous experiences, the first words that
come to mind when thinking about Asus are outstanding performance and
quality. I was happy when I got the chance to review their latest
offering, the Asus Extreme N7800GT. This card is based on the
G70, NVIDIA 7800GT design.
| Architecture | NV40 | G70 | G70 | | Card | Geforce 6800 Ultra | Geforce 7800GTX | Geforce 7800GT | | Memory Interface | 256-bit | 256-bit | 256-bit | | Memory Bandwidth (GB/s) | 35.2 | 38.4 | 32 | | Fill Rate (Megapixels) | 6400 | 6800 | 6400 | | Manufacturing Process | 0.13nm | 0.11nm | 0.11nm | | Pixel Pipelines | 16 | 24 | 20 | | Transistor Count | 220M | 302M | 302M | | Vertex Pipelines | 6 | 8 | 7 | | Core Clock | 400 | 430 | 400 | | Memory Clock | 1100 | 1200 | 1000 | Memory Size
| 256Mb | 256Mb | 256Mb |
In June this year NVIDIA shocked the world by releasing a new high
end graphics chip, the G70. The Geforce 7800GTX was available the same
day NVIDIA announced it. 2 months down the road in August, they
did it again. This time it was the Geforce 7800GT and it was also
available at launch. This is how is should be and not paper
launch a graphics card like both NVIDIA and ATI have done in the past.
NVIDIA has certainly raised the bar so let’s hope this becomes
the normal trend and not just a one time deal.
And as many of you are aware of the 7800GTX is still the king of the
hill. No readily available competitor’s graphic cards can
currently compete. The only downside to the 7800GTX is the price, the
cost is roughly $600 and not many people has that kind of money to
spend on just a graphics card. Fear not my friends; the
Asus Extreme is here to save the day. You can find the Asus 7800GT for
as little as $410; that’s $200 cheaper than the GTX, $150 cheaper
than the ATI X850XT PE and $100 cheaper than the 6800 Ultra.
Why is it cheaper? The 7800GT has 20 pixel pipelines compared to
24 the 7800GTX has. It only has 7 vertex pipe lines compared to
the 8 the GTX has. The other major differences are the 200 MHz
lower clock speed on the memory and 30 MHz lower speed on the
core. Very soon we will find out how that impacts performance
compared to the 7800GTX. The 7800GT features are identical to the
7800GTX and is of course SLI ready as well.
Scalable Link Interface (SLI)
SLI is a method for linking two (or possibly more) video cards together
to produce a single output. Back in 1998 3dfx introduced a technology
called Scan Line Interleave and was used in the Voodoo 2 line of
graphics technology. With the introduction of the NV40 NVIDIA
reintroduced the technology in 2004 and of course G70 is also
supporting this technology.
With SLI, in theory it is possible to roughly double the amount of
graphic power by adding a second video card. A single GPU is supported
by an x16 PCI-e slot, which can be reprogrammed to two x8 PCI-e slots
to support two video cards in SLI mode. The Forceware drivers
distribute the workload in 2 ways. SFR (Split Frame Rendering splits
the workload 50/50 between the 2 GPU’s and AFR (Alternate Frame
Rendering) in which one GPU processes the current frame, while the next
frame is processed by the second card.
Shader Model 3.0
Shader Model 3.0 is the latest DirectX 9 has to offer, Shader Model 3.0
introduced, Vertex Texture Fetch, Geometry Instancing, and Dynamic
Branching. Many of you have heard of HDR (High Dynamic Range Rendering)
which more games have now begun to support. The first game to support
Shader Model 3.0 and HDR was Far Cry. With HDR enabled Far Cry became a
new game considering how realistic it looked. There was a
downside as well; the performance hit was often quite big. Now with the
G70, NVIDIA has greatly improved the HDR performance compared to the NV
40.
There are many different HDR effects that can be applied:
* Blooming is used by designers to create a "blurred effect" on the bright edges in a scene, emulating a cameras overexposure.
* HDR Skybox is authored by painting multiple exposures of the sky to allow for real-time exposure adjustment.
* HDR Cube Maps are generated by the engine, using the HDR skybox in
conjunction with the HDR light sources and HDR light maps. HDR Cube
Maps allow for an objects reflection to be cast in a manner that more
accurately corresponds with the brightness of the source.
* HDR Refraction Effect is when HDR light is transmitted through
refractive materials, and takes on the relevant properties of those
materials.
* HDR Light Maps are generated through a radiosity process, taking light bounces/global illumination into account.
* Exposure Control enables "eye adjustments" to allow you to see a
different range of details in dark scenes and in over bright areas.
Most games that have been developed in the past year and support Shader
Model 3.0 has most likely had NVIDIA hardware available during for the
development process. NVIDIA has been alone on that front as ATI
chose not to implement Shader Model 3.0 in their current generation of
Graphic Cards.
As mentioned in previous articles, I really like HDR. It adds a far
more realistic look to your games with it enabled. With the Asus
Extreme N7800GT you will have no problem enjoying your gaming
experience at full quality. More games are starting to take advantage
of HDR rendering, the newly released Splinter Cell, the upcoming Unreal
Tournament 2007 and the soon to be released Half-Life 2 Lost coast map
to name a few. The only drawback to HDR is of course that you
cannot enable AA.
Intellisample 4.0
* Advanced 16x anisotropic filtering (with up to 128 Taps)
* Blistering-fast antialiasing and compression performance
* Gamma-adjusted rotated-grid antialiasing removes jagged edges for incredible image quality
* Transparency multisampling and transparency supersampling modes boost antialiasing quality to new levels
* Support for normal map compression
* Support for advanced lossless compression algorithms for color,
texture, and z-data at even higher resolutions and frame rates
* Fast z-clear
The Asus Extreme N7800GT also has support for the two new antialiasing
modes that where introduced with the 7800GTX, transparency adaptive
supersampling and transparency adaptive multisampling which according
to NVIDIA increase the quality and performance of antialiasing.
Transparency adaptive super sampling and multisampling take additional
Texel samples and antialiasing passes to enhance the quality of
thin-lined objects such as chain link fences, trees, and vegetation.
These types of objects are generally rendered on very simple polygon
models (or even one polygon). The complexity of the final image (a
group of branches or vegetation) comes from the texture that is mapped
onto the polygon. Conventional antialiasing does not help this
situation, because the edges of the vegetation or branches are actually
inside the projected texture. Pixels inside a polygon are not touched
by current antialiasing methods.
Transparency adaptive multisampling also improves antialiasing
quality - with even higher levels of performance because one texel
sample is used to calculate surrounding subpixel values. Although
transparency adaptive multisampling is not as high quality as the super
sampling method, its increased efficiency balances improved image
quality and high levels of performance. The visual improvements of
adaptive supersampling are obvious when compared to generic
supersampling/multisampling approaches.
Once you get used to TAA you will have a hard time giving it up, I know
I have and the performance impact is so small as well that you
don’t have to give it up.
CineFX 4.0
* Vertex Shaders
* Support for Microsoft DirectX 9.0 Vertex Shader 3.0
* Displacement mapping
* Geometry instancing
* Infinite length vertex programs
* Pixel Shaders
* Support for DirectX 9.0 Pixel Shader 3.0
* Full pixel branching support
* Support for Multiple Render Targets (MRTs)
* Infinite length pixel programs
* Next-Generation Texture Engine
* Accelerated texture access
* Up to 16 textures per rendering pass
* Support for 16-bit floating point format and 32-bit floating point format
* Support for non-power of two textures
* Support for sRGB texture format for gamma textures
* DirectX and S3TC texture compression
* Full 128-bit studio-quality floating point precision through the
entire rendering pipeline with native hardware support for 32bpp,
64bpp, and 128bpp rendering modes
According to NVIDIA the new CineFX 4,0 engine includes support for
Microsoft’s Longhorn using the Windows Graphics Foundation
1.0. CineFX 4.0 also supports Ultrashadow II; a feature NV 40
introduced about 15 months ago with the previous generation of cards.
PureVideo
* Adaptable programmable video processor
* High-definition MPEG-2 and WMV9 hardware acceleration
* Spatial-temporal de-interlacing
* Inverse 2:2 and 3:2 pull-down (Inverse Telecine)
* 4-tap horizontal, 5-tap vertical scaling
* Overlay color temperature correction
* Microsoft Video Mixing Renderer (VMR) supports multiple video
windows with full video quality and features in each window
* Integrated HDTV output
According to NVIDIA, the implementation of the technology ensures
smooth playback of high definition MPEG -2 and Windows Media Video
files through NVIDIA hardware, without relying heavily on the host CPU.
 With that in mind, I moved my PC to the living room and fired up some
High Definition material and, well I had a hard time picking my chin up
from the floor when I saw it on the Plasma TV. It looks absolutely
stunning and the Asus Extreme N7800GT takes the load off the CPU very
well. According to task manager the cpu load was about 22-30% on my
AMD64 3800+ and in some cases topping to 40%.
The
N7800GT has the power to play all the current and upcoming games
extremely well and as a bonus it has the built in PureVideo engine that
supports de-interlacing with HD resolutions up to 1080i. The PureVideo
engine is programmable and will make new video features easier to
implement. It will also be able to support new video formats through
driver updates, the N7800GT supports WMV-HD decode acceleration that
can offload video decoding from the CPU onto the GPU up 40%.
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