there's one thing a rash of new product launches means it's
that you'll have to learn a whole new batch of model numbers,
prefixes, suffixes and acronyms. Just in the graphics card
arena so far this year we've had to come to terms with "Ultras",
"Pro's", "GT's", "XT's", "XT-PE's",
"PCI-E" and "GDDR3", and the year's
not done yet!
letters we're concerning ourselves with today are "XT-PE",
or to put it in simple terms, the fastest Radeon X800 your
money can currently buy you. The PE denotes that the card
is a "Platinum Edition" version, and as we'll
find out shortly, the "XT" must surely stand for
Radeon X800 XT-PE I'm looking at today was supplied one
of the smaller fish in the pixel pond, Connect3D. Despite
being a less prominent player, Connect3D have consistently
produced high quality products at great prices and are known
for their general "no frills" approach by catering
to those who favour value for money over free, and possibly
duplicated software titles and dubious in-box incentives.
With 600 employees and a manufacturing presence in Zhenzhen,
China however, Connect3D are no fleeting presence. They
may not have the marketing clout enjoyed by some of ATi's
bigger first-tier partners but have no doubts about their
capabilities, either to supply the products or to support
up ATi's latest generation of graphics card, the XT-Platinum
Edition has the full compliment of 16 pipelines throwing
data through them at 520 million cycles per second and feeding
256MB of DDR3 memory running at 560million Hertz (560MHz)
which is 1.12GHz effectively. It doesn't seem so very long
ago we were all celebrating the first CPU to run at 1GHz!
you've yet to see an X800 in the flesh you're no doubt expecting
it to be a rather industrial looking dual-slot part with
more power connectors than memory chips and with the dimensions
of a small dining table, but as we'll see on page three
it's in fact a very elegantly engineered piece of kit that's
no bigger than the earlier 9800XT.
those of you who are familiar with the technical details
of the X800 please skip over to the next page. If you want
a quick reminder of what the X800 is all about here's a
quick recap from some of our previous reviews.
POWER CONNECTION REQUIREMENTS
of 'Xtreme performance GDDR3 memory accelerates the
latest cutting edge 3D applications
quad-channel GDDR3 memory interface
'Xtreme parallel pixel pipelines
the AGP 8X and AGP 4x standard, providing a high-speed
link between the graphics board and the rest of the PC
programmable vertex shader pipelines
support for DirectX® 9.0 and the latest OpenGL® functionality
SMARTSHADER™ HD technology allows for support for
Microsoft® DirectX® 9.0 programmable vertex and pixel
shaders in hardware as well as OpenGL® via extensions.
HD technology provides enhanced image quality by removing
jagged edges and bringing out fine texture detail, without
High quality 4:1 Normal Map Compression delivers beautiful
scenes without the performance hit.
VIDEOSHADER™ HD engine uses programmable pixel shaders
to accelerate video processing and provide better-looking
Z™ HD is optimized for performance at high display resolutions,
including widescreen HDTV resolutions.
RADEON™ X800 PRO must be connected to the computer? power
supply to meet its performance and high-speed memory requirements.
Remove the power cable from the hard drive.
In order to supply the ATI Graphics Accelerator card with
the necessary power, we have included the Power Extension
Use the Power Extension Cable to connect the Radeon X800
PRO to the computer? hard Drive power connector.
2. Connect the 4-pin connector of the Power Extension Cable
to the RADEON™ X800 PRO power connector.
3. Connect the Power Extension Cable to the power supply connector.
4. Connect the Power Extension Cable to the Hard Drive connector.
not pull any punches here, the R420 isn't a massively different
chip to its predecessor the R300. There are however a few
important additions and refinements so before we move on
let's take a quick look at the more important ones.
of building even the most simple of objects from many tens
of thousands of polygons, the best way to add detail to
the surface of an object is though the clever use of high
resolution textures or manipulation of the available lighting
information. Imagine a low ploygon model, it looks angular
and false. Now drape it with a high quality texture and
suddenly it loses some of its angles and starts to resemlble
what it's meant to be. At this stage though the texture
still looks flat and lacking any depth and real detail.
than pump up the polygon count, a far lest costly way to
increases surface detail is to use high resolution normal
Normal is a piece of data showing the way in which light
interacts with a surface at a given point. The problem is
that models made from too few polygons contain too few normals
to create a properly lit surface. What 3DC does is to create
a high resolution normal map which stires vastly more information
than would normally be generated and then apply that to
the object, so giving the illusion that it contains far
more detail than it really does.
this method uses pixel operations rather than geometry functions,
it tends to be more efficient on consumer graphics cards
which are often optimized for pixel data throughput.
course the benefits from 3Dc are slowly being eroded as
polygon counts and texture quality inreases in modern games
but ultimately it's a feature worth having. 3Dc works on
any two-channel data formats and is not particularly limited
to normal maps.
of the big features introduced with ATi's CATALYST 4.7 drivers
was the mysterious Temporal Antialiasing setting.
covered the principle before but for those who've not heard,
Temporal AA works by staggering its sample patterns across
two frames of animation. What this means is that frame one
performs a 2x antialiasing calculation and frame two carries
out the same procedure but samples from alternative positions.
The end result is that two slightly different frames are
created which, provided they are displayed quickly enough,
combine to give the illusion that it's all happening in
a single frame. Enable temporal AA and in theory you get
twice the level of antialiasing you've actually set. Ingenious!
FSAA Viewer 5.1 does a nice job of showing the two sample
patterns. In this case I used a 4xAA setting though by far
the most effective, and in many cases useful setting will
surely be the 2x setting. This allows near 4xAA quality
under the right conditions but with only the performance
penalty normally associated with a 2x sample pattern.
course it's not all good news. The problem with this method
antialiasing is that when framerates drop to a low enough
level there's a very visible and slightly distracting edge
flicker as the transitions between odd and even frames starts
to become an issue. This, as you might expect, becomes more
of a distraction with high contrast edges. Ironically this
is more of a problem using modern monitors with their low
persistence phosphors than it would have been with older
displays which weren't quite so quick to switch their pixels.
have partly dealt with the flicker issue by having the drivers
disable Temporal AA as soon as framerates drop below a fixed
threshold, currently 60fps, but this in itself can cause
distraction as, in some games, the switching becomes quite
noticeable. I'm not sure if it's a physical lag or just
that it catches the eye but it is visible in some games,
and less so in others.
rather enlarged example below is from an edge that was originally
angled but has been placed horizontally here for ease.
Animation Showing Odd and Even Frame Edge Pixels
can't get the animation to run at the 100 plus frames per
second needed to get a reasonable effect but if we shrink
the selection down and speed it up as much as possible you
can hopefully get an idea what Temporal AA achieves.
you'd expect it's impossible to grab a screenshot of the
effect in action as a single frame will always be using
one or other of the two sample patterns, and I'm not certain
that combining and averaging then would give a true representation
of what you actually see in-game. Temporal AA is however
a worthwhile feature and when used in the right situations
the effect is extremely impressive. I'd like more control
over the threshold level personally but maybe that will
come. I'm also curious to see what other advanced effects
could be "shared" across multiple frames, perhaps
super hi-res textures or complex ray tracing effects?
the performance hit, if any, is something else we'll belooking
at. The problem here is that in order to use Temporal AA,
you need to have VSync enabled which impacts on the results.
Even with a 120Hz refresh rate I wasn't able to find a benchmark
that would run consistently at between 60 and 120 fps for
than the occasional flickering, the only problem I encountered
with TemporalAA was that in one, isolated incident, it seemed
to introduce an element of moiré into a scene where
one of the textures featured tightly packed diagonals and
I'd be curious to hear if anybody has noticed anything similar
in any other games titles or whether this was an isolated
definition gaming with up to 16 pipelines, up to 80 concurrent
shader operations per clock, 6 vertex shaders delivering
in excess of 750million vertices per second, improved Centroid
sample and new Temporal Antialiasing plus FULLSREAM video
deblocking, HDTV support, HYPER Z HD and more, and all in
a single slot solution.
tempting? Let's look at the hardware.