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The G80 Architecture
NVIDIA’s GeForce 8800 was the product that gave birth to the new GPU Computing model.
Introduced in November 2006, the G80 based GeForce 8800 brought several key innovations
to GPU Computing:
• G80 was the first GPU to support C, allowing programmers to use the power of the
GPU without having to learn a new programming language.
• G80 was the first GPU to replace the separate vertex and pixel pipelines with a single,
unified processor that executed vertex, geometry, pixel, and computing programs.
• G80 was the first GPU to utilize a scalar thread processor, eliminating the need for
programmers to manually manage vector registers.
• G80 introduced the single-instruction multiple-thread (SIMT) execution model where
multiple independent threads execute concurrently using a single instruction.
• G80 introduced shared memory and barrier synchronization for inter-thread
communication.
In June 2008, NVIDIA introduced a major revision to the G80 architecture. The second
generation unified architecture—GT200 (first introduced in the GeForce GTX 280, Quadro FX
5800, and Tesla T10 GPUs)—increased the number of streaming processor cores
(subsequently referred to as CUDA cores) from 128 to 240. Each processor register file was
doubled in size, allowing a greater number of threads to execute on-chip at any given time.
Hardware memory access coalescing was added to improve memory access efficiency.
Double precision floating point support was also added to address the needs of scientific and
high-performance computing (HPC) applications.
When designing each new generation GPU, it has always been the philosophy at NVIDIA to
improve both existing application performance and GPU programmability; while faster
application performance brings immediate benefits, it is the GPU’s relentless advancement in
programmability that has allowed it to evolve into the most versatile parallel processor of our
time. It was with this mindset that we set out to develop the successor to the GT200
architecture.
NVIDIA’s Next Generation
CUDA Compute and Graphics Architecture, Code-Named “Fermi”
The Fermi architecture is the most significant leap forward in GPU architecture since the
original G80. G80 was our initial vision of what a unified graphics and computing parallel
processor should look like. GT200 extended the performance and functionality of G80. With
Fermi, we have taken all we have learned from the two prior processors and all the applications
that were written for them, and employed a completely new approach to design to create the
world’s first computational GPU. When we started laying the groundwork for Fermi, we
gathered extensive user feedback on GPU computing since the introduction of G80 and GT200,
and focused on the following key areas for improvement:
