NVIDIA GF100 Fermi Architecture and Performance PreviewWed, Jan 20, 2010 - 12:00 AM
Demo Time: Ray Tracing & Tessellation
NVIDIA also showed us a demos that we recorded as they showed them to us. So, you can watch they ones you want and hear NVIDIA explain the demos to the media in our press briefing.
Ray tracing is seen by many as the future of graphics, either by itself or in conjunction with rasterization. With GF100, interactive ray tracing becomes possible for the first time on a standard PC. Ray tracing has typically been challenging to run efficiently on the GPU. Ray tracing operates recursively, whereas GPUs mostly operate iteratively. Rays have unpredictable directions, requiring lots of random memory access. GPUs typically access memory in linear blocks for efficiency.
GF100’s compute architecture was built specifically with ray tracing in mind. GF100 is the first GPU to
support recursion in hardware, enabling efficient
ray tracing and a host of other graphics
algorithms. GF100’s L1 and L2 caches greatly
improve ray tracing efficiency by improving
performance for fine-grained memory accesses.
The L1 cache enhances memory locality for
neighboring rays whereas the L2 cache amplifies
bandwidth to the framebuffer.
GF100 excels not just at standard ray tracing, but
also at advanced global illumination algorithms
such as path tracing. Path tracing uses a much
larger number of rays to collect ambient lighting
information from the scene. Early evaluations of
path tracing show GF100 performing up to four
times faster than GT200.
To sustain performance,
a game may use ray
tracing selectively. For
can be used to perform a
first pass on the scene.
Pixels that are identified
as reflective may be
further processed via ray
tracing. This hybrid
model of rendering
enables fast performance
with great image quality.
The Hair demo uses tessellation, geometry shaders, and physical simulations.
The Water demo (right) uses tessellation in large environments.