The evolution of microprocessors has been targeted to increased performance. To achieve this goal, we tried to decouple the system bus by the CPU, with the use of buffer and the cache, which constitute the prefetch queue. In addition we tried to reduce the execution time of each instruction, and introducing superscalarità pipeline, in order to improve throughput, or to make multiple instructions simultaneously.
Thanks to the increasing integration capability has reached the multi-core systems that have multiple processors on a single plate.
The main Intel architectures, which have followed in chronological order are:
-X86-16 (IA-16), the routing is done on 16bit (offset).There are records to 8-16bit. This architecture is a native of 8086 and 286.
-X86-32 (IA-32), the routing is done on 16-32bit (offset).Registers are 8-16-32bit. This architecture is a native of 386, 486 and Pentium.
-X86-64, the address is made of 16-32-64bit (offset).There are records from 8-16-32-64bit. This architecture is native on Pentium4.
Note that the IA-64 is a completely different technology, called Itanium. It is therefore not the same as X86-64.
Note that when we talk of address space does not mean never the parallelism of the bus, but there is talk of addressing the programmer sees. For example nell'X86-64 have a 64-bit addressing, even though in reality the bus has many more bits.
The Pentium III was produced in 1999 and consists of about 44 million transistors with 370 pins. It has two levels of cache to 256KB. In more advanced models can operate at a maximum frequency of 1.5GHz with a 133MHz clock. It 's powered by a single voltage of 1.65V.The Pentium 3 has an address space ranging from 4GB to 64GB. It is able to operate both in real mode (during the ignition phase), which in a secure manner.
The Pentium IV was produced in 2000 and consists of about 70 million transistors. It has two levels of cache 2MB. It operates at a maximum frequency of 3.8GHz. The Pentium IV was released in less powerful version under the name of Celeron. The version was called Dual Core Pentium D.
The Core 2 was released in 2006 and consists of two Pentium CPUs. E 'equipped with a 3GHz clock speed and cache very efficient. Starting in 2007 were released by new versions of Intel Dual Core processors, which also support 64bit. This family of processors is known as the Core 2 Duo.