Hardware Reference
In-Depth Information
video controllers. AMD also released its Phenom II series of multi-core (up to six-core)
processors with support for both DDR2 and DDR3 memory in 2008. In 2011, Intel re-
leased the “Sandy Bridge” second generation of Core i-series processors, including four-
core and six-core processors with HT Technology, supporting up to 12 execution threads.
Some models include an on-die video controller that permits dynamic switching of re-
sourcesbetweenGPUandCPU(TurboBoost2.0),dependingonthetypeofprocessingbe-
ingperformed.In2011,AMDintroduceditsFusionprocessors,whichincorporateRadeon
graphics, low power consumption, and acceleration for video, photo, and web operations.
Note
Intel began to develop mobile versions of its processors in the early 1990s with the develop-
ment of the 386 processor. Both Intel and AMD have developed mobile versions of almost
all of their processors.
Although a mobile processor may have the same code name, a similar model number, and
be based on the same general architecture as its desktop counterpart, it might feature lower
clock speeds, smaller cache sizes, and different implementations of some features. The pro-
cessor features for a particular processor family discussed in this chapter apply to desktop
processors. For more information about mobile processors in a given processor family, see
the Intel or AMD websites.
16-Bit to 64-Bit Architecture Evolution
The first major change in processor architecture was the move from the 16-bit internal ar-
chitecture of the 286 and earlier processors to the 32-bit internal architecture of the 386
and later chips, which Intel calls IA-32 (Intel Architecture, 32-bit). Intel's 32-bit architec-
ture dates to 1985. It took a full 10 years for both a partial 32-bit mainstream OS (Win-
dows95)aswellasafull32-bitOSrequiring32-bitdrivers(WindowsNT)tosurface,and
it tookanother 6years forthe mainstream toshift toafully 32-bit environment forthe OS
anddrivers(WindowsXP).That'satotalof16yearsfromthereleaseof32-bitcomputing
hardware to the full adoption of 32-bit computing in the mainstream with supporting soft-
ware. I'm sure you can appreciate that 16 years is a lifetime in technology.
Now we are near the end of another major architectural jump, as Intel, AMD, and Mi-
crosoft have almost completely shifted from 32-bit to 64-bit architectures. In 2001, Intel
had introduced the IA-64 (Intel Architecture, 64-bit) in the form of the Itanium and Itani-
um 2 processors, but this standard was something completely new and not an extension
of the existing 32-bit technology. IA-64 was announced in 1994 as a CPU development
project with Intel and HP (code-named Merced), and the first technical details were made
available in October 1997.
