Hardware Reference
In-Depth Information
Multicore Processors
To keep making better and faster processors every year, manufacturers constantly have to
fi nd ways to increase the number of instructions per second. One way they have done this is
to increase the complexity of the processor design. Another is to house multiple processors
together and have them work in unison.
For many years, motherboards have been available that hold multiple, separate
processors, each with its own slot on the motherboard. This technology is limited, though,
because of the distance between the processors and the speed limitations on the bus
pathways between them. As mentioned earlier, manufacturers found a solution to this by
creating multicore processors that combine several processors into a single package. These
processors look like one chip from the outside but actually have several separate processor
cores inside.
Cell Microprocessors
Cell microprocessors are a hybrid between multiple-core processors and specialized
systems (such as high-end graphics cards), created by a partnership between Sony,
Toshiba, and IBM. The result is a system that is better equipped for simulation, imaging,
and gaming solutions. Sony uses a cell microprocessor for its PlayStation 3 gaming
system, with eight cells (or processors) running the console. The Xbox 360 differs in that
it uses a three-core technology, the Xenon.
Motherboards are still available that hold more than one processor, especially
boards designed for servers. By combining multiple multicore processors
in a system, you can increase the processing power many times over. For
example, if you have a single-core processor running at 3 GHz, a quad-core
processor could elicit the combined potential of 12 GHz, and a board with
four quad cores could theoretically have a processing potential equivalent of
48 GHz. Be advised, however, that in the transaction of commands between
multiple processors, there is an inevitable loss in performance.
EXERCISE 1.2
Comparing Processors
Intel and AMD list their processors and specifi cations, including the cache size of each of
their products. Visit
http://ark.intel.com/Default.aspx
and
http://products.amd.com/
en-us/DesktopCPUResult.aspx
to identify current processors, their speeds (in GHz), cache
sizes, and the numbers of cores and clock speeds per core.
