At this point NVIDIA had several opportunities. One was for example
that they could stick with the Tegra 2 design and optimize it for lower leakage
power. Another more radical approach would have been to use TSMCs LP
manufacturing process. But this would have thrown back the company from a
performance perspective. Instead they headed for a much more creative way. What
they did is to create a five core SoC whereas the fifth core is called the
companion core. This companinon core is made using the TSMCs LP process which
means that there will be very low leakage powers. This processor takes over when
a Tegra 3 device is locked for example, so all the background processes will run
with on a core that uses way less power. Furhtermore NVIDIA integrated power
gating. This means that the core logic can be deactivated. Core which are not
needed will therefore be shut down and drain no power at all. Like this NVIDIA
elegantly solved the problem with the leakage power and as a consequence there
could now even be smartphones based on NVIDIAs Tegra 3 SoC.
A look at other parts of the SoC reveals that Tegra 3 also went through
some evolution processes. The new SoC for example features NEON-Support which is
being realized via a ARM MPE (Media Processing Engine). To keep the Tegra 2 die
as compact as possible NVIDIA decided to not support NEON with Tegra 2. Actually
NEON is an instruction set which allows 2D as well as 3D acceleration.
Furthermore it can also accelerate sound synthesis.
If we also take a closer look at
the GPU we don't see a lot of differences. There is also more evolution than
revolution. Whereas Tegra 2 had vier pixel and four vertex shaders, Tegra 3 now
has twice as many shader units but still the same amount of vertex processors.
The core count went up to twelve.