NVIDIA GeForce 256 Introduction
Voodoo 4 vs. GeForce 256
Now there is much debate as
to how better graphics can be brought into gaming. Quite unsurprisingly 3dfx who have
concentrated on more fill-rate is claiming that is the way to go. Not directly by raw
fill-rate but by allowing for T-Buffer technology, especially anti-aliasing, which will
greatly improve the visual quality of games. Yet for current games the GeForce 256 seems
quite capable at 1024x768, which at 60 fps has been the 3dfx anathema as well. In a recent
interview 3dfx were stating that their card will be superior at higher resolutions. True
but this is also spin-doctoring because using the T-Buffer is meant to give good frame
rates at 1024x768, about the same resolution that the GeForce will run with it's own
feature set fully enabled and at similar frame rates. So both these products will perform
their respective tricks and hope to give you 60 fps at 1024x768. The ideal situation of
course could be to have a Glaze3D 2400 with the Thor geometry co-processor! This would
allow the same geometrically detailed levels and models but at a higher resolution.
One thing about the T-buffer
that is really cool is that it will not require you to wait for any games to support it
for anti-aliasing! It's just a driver switch to turn it on. Of course the other features
are not as easy. In fact since they are cinematic effects they will need a more
fundamental shift in the game design which may actually deter developers from fully
utilising it because they will be blocking out a large potential customer base in doing
so. Things like the use of depth-of-field to simulate a blurred/concussion effect should
not present such problems though.
With the GeForce developers
will have to make more detailed levels than is currently used. So you will see this only
in new games. It is often said that developers will not bother due to the need to support
a large base of cards without such geometry features. But with most of the good 3D engines
supporting dynamic level-of-detail (LOD) often based on the frame-rates you are getting
this shouldn't be as big an issue as some would like you to believe.
Here's a little math for you
to consider,
A single frame at 1024x768 has 786432 pixels.
At 60 fps this works out to 47185920 or 47.2
MegaPixels to be drawn in a second.
If the entire screen is made of dual textured
pixels the GeForce will be able to draw 240 MegaPixels in one second.
A
very simplified view. This does not take into account overdraw, which would increase the
required fill-rate per frame by about 50% or more, and overheads such as latency in
accessing texels from video memory. Still with the memory (especially) and other
subsystems (geometry should be no problem) permitting 60 fps at 1024x768 should be quite
possible.
Just keep in mind that this
section has been based on comments by 3dfx (regarding 1024x768 @ 60 fps with T-Buffer) and
NVIDIA (again that the card is meant to do 1024x768 @ 60 fps). Also from what is known of
the performance of the GeForce 256 on beta drivers (tad bit over 30 fps at 1600x1200 in
Q3) and is not concrete.
Next page: Hardware Lighting
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