Club3D X850 XT - 02 - Features
||Radeon X850 XT - R480
||Samsung K4J55323QF-GC16 (1.6ns)
||256 MB 256-bit GDDR3
|Engine Clock Speed
|Memory Clock Speed
||8.6 Giga pixels /sec
||VGA / DVI-I / D-Sub
The R480 is not very different from the previous high end R430. It too is
built using the 0.13 micron low-k fabrication process and still features
Pixel Pipelines and 6 parallel Vertex engines.
As you can see from the ATITool screenshot, the GPU and Memory clocks for
the X850 XT are set to 520MHz and 540MHz respectively.
The card is equipped with 8x32MB=256MB of GDDR3 memory
from Samsung. The parts used are the famous K4J55323QF-GC16 which are
especially for high-end graphics cards.
The 16 in the memory's name corresponds to 1.6ns memory
speed. Dividing 1 by 1.6, we get the maximum supported memory clock frequency.
Therefore 1/1.6=600MHz which is quite a difference from the 540MHz. Hopefully,
the fansink on the X850XT will provide the card with enough cooling to sustain
the clock closer to 600MHz.
Here's a table containing the differences between the X800 XT PE and the new X850 XT and XT PE:
X800 XT PE
||X850 XT PE
To understand what 3Dc does, we need to quickly run through a brief
discussion on normal maps.
You can think of a normal as an arrow pointing outwards from a surface at a
90 degree angle in order to quickly access its angle difference from different
points of lighting.
First, a model with an extremely high polygon count is created (i.e 15000 polygons)
and then one with less (1000 polygons) and that is the one that we'll eventually
keep. Running a simple program calculates the differences between the two models
and stores it as a normal map texture. Before rendering the final model in the
game, the normal map texture is applied on the low polygon model and pixel shader
instructions are used to compute real time lighting.
|A quick example of Normal Mapping (not 3Dc!)
Normal mapping is greatly used in some of the most successful
game titles of our days, like Far Cry, Half Life 2 and Doom 3. However, the
with Normal mapping is the great limitation on the texture size due to the
lack of compression.
To get a peek at what would happen if none of the textures were
compressed in a recent game, try Doom 3 and set the details to Ultra High. As
suggested by Id Software, Doom3's publisher, the Ultra High detail level requires
a graphics card with 512Mb RAM. In case you're not really into the graphics
card market there is no card with 512Mb RAM, yet.
Such is the case with normal mapping. The current texture compression
algorithms, DXTC and S3TC, are inapplicable on normal mapping textures as they
produce block artifacts, so programmers usually avoid using them.
3Dc is the solution to this problem with an algorithm that splits
up the texture into blocks. Then compressing each block, it is able to achieve
up to 4:1 compression.
When using 3Dc you can get much better quality textures with the same performance from your card.
The bad thing about 3Dc is that we'll have to wait until the game developers
incorporate it into their engines or release a patch that takes advantage of
it. Ubisoft was supposed to be the first to include 3Dc support into their much
awaited Far Cry patch 1.3. However, as we found out, there is no actual difference
in the game despite the addition of the console command "EnableCompressedMaps".
• Full hardware acceleration for Microsoft® DirectX®
9.0 programmable vertex and pixel shaders in
DirectX 9.0 Vertex Shaders
- Vertex programs up to 65,280 instructions
with flow control
- Single cycle trigonometric operations
(SIN & COS)
DirectX 9.0 Extended Pixel Shaders
- Up to 1,536 instructions and 16 textures per
- 32 temporary and constant registers
- Facing register for two-sided lighting
- 128-bit, 64-bit & 32-bit per pixel floating point
- Multiple Render Target (MRT) support
• Complete feature set supported in OpenGL®
• 2x/4x/6x Anti-Aliasing modes
Sparse multi-sample algorithm with
gamma correction, programmable
sample patterns, and centroid sampling
Lossless Color Compression (up to 6:1)
at all resolutions, including widescreen
2x/4x/8x/16x Anisotropic Filtering modes
- Up to 128-tap texture filtering per
- Adaptive anisotropic filtering algorithm
with bilinear (performance) and trilinear
HYPER Z™ HD
• 3-level Hierarchical Z-Buffer with Early Z Test
• Lossless Z-Buffer Compression (up to 48:1)
• Fast Z-Buffer Clear
• Z cache optimized for real-time shadow rendering
• Optimized for performance at high display
resolutions, including widescreen HDTV resolutions
• Seamless integration of pixel shaders and video in
• FULLSTREAM™ video de-blocking technology for
Real, DivX, WMV9 and WMV10 formats
• VIDEOSOAP™ noise removal filtering for captured
• MPEG1/2/4 decode and encode acceleration
Hardware Motion Compensation, iDCT, DCT and
color space conversion
• All-format DTV/HDTV decoding
• Adaptive Per-Pixel De-Interlacing and Frame Rate
Conversion (temporal filtering)