Types of CPU
The two major CPU manufacturers are Intel and AMD (Advanced Micro Devices
). Both of these companies were founded in the late 1960s.
Intel produced 8-bit processors from 1972 to 1976. The first widely adopted 8-bit microprocessor was the Intel 8080, being used in many hobbyist computers of the late 1970s and early 1980s. 16-bit processors were produced from 1978 to 1982 which included the Intel 80286, also known as the 286, and introduced by Intel in 1982. 32-bit processors were introduced in 1985 with the release of the Intel 80386, also known as the 386, in 1985.
|Pentium Pro ||1995||166MHz-200MHz|
|Pentium II ||1997||233MHz to 450MHz|
|Pentium III ||1999||450MHz to 1.26GHz|
|Pentium 4 ||2000-2008||1.3Ghz to 3.8GHz|
Starting from 1998 Intel released the Xeon
brand which was targeted at the high-end server market, and in the same year they released the Celeron
brand which was a low-end processor for budget PCs. The first 64-bit processors were the Intel Itanium & Itanium 2 released in 2001 & 2002.
When CPU manufacturers hit the practical limit of 4GHz in 2002-2003 they decided to combine two or more CPUs into a single chip creating multiple core processors.
The Intel Core 2
were 64-bit multi-core processors (2 or 4 cores) and were released from 2006 to 2011 with a clock rate of 1.06GHz to 3.5GHz.
The Nehalem microarchitecture
was released in 2008, and Intel introduced a new naming scheme for its Core processors: Core i3
, Core i5
, and Core i7
With the Intel Nehalem
CPUs, the Memory Controller has moved from the Northbridge (see chipset page) to the CPU which significantly improves performance as the CPU can access the RAM directly. More recently the Sandy Bridge
CPUs which were introduced in 2011 have an integrated Memory Controller and Graphics (PCIe) which allows the CPU to access the RAM and Graphics (PCIe) directly making the Northbridge chip redundant.
Intel's Ivy Bridge
CPUs came out at the end of 2012 and are backward compatible with the Intel Sandy Bridge
CPUs. Ivy Bridge
was succeeded by Haswell
microarchitecture in 2013, Broadwell
(2014), and Skylake
(2015) which supports DDR4 SDRAM system memory.
A comprehensive list of Intel Processors can be found here.
In 1982, AMD signed a contract with Intel to become a licensed second-source manufacturer of 8086 and 8088 processors. At the time, IBM (International Business Machines
) produced the IBM Personel Computer and was one of the world's largest companies which dominated the computer industry. IBM's policy at the time was to require at least two sources of processors for its IBM PC, so Intel had to license another company (AMD) to also manufacture microprocessors in order to secure the contract.
Later, under the same agreement AMD produced the Am286 which was essentially an Intel 286. In 1986, Intel cancelled its agreement with AMD and refused to supply any further technical details causing years of legal wrangling which went on until 1994. Intel were not happy that AMD were producing 386 CPUs and said the agreement was for the 286 and prior processors only. In 1991, AMD released the Am386 which was a clone of the Intel 386 and won their court case to sell these processors. Later they released the Am486 a clone of the Intel 486, and then the Am5x86 processor was released in 1995 which was a clone of the Intel Pentium. In 1996, AMD decided to develop an entirely in-house processor called the AMD K5 which was comparable to the Intel Pentium Pro.
| Year || Clock rate |
| Am*86 || 1991 || 20MHz to 150MHz |
|AMD K5 ||1996||75Mhz to 133Mhz|
|AMD K6 ||1998||166Mhz to 550Mhz |
|AMD K7 ||1999||500MHz to 2.33GHz|
|AMD K8 ||2003||1.6GHz to 3.2GHz|
The AMD K8
included the AMD64 64-bit processor and the AMD64 also had an on-chip memory controller so that it could access the RAM directly. The Athlon 64 X2 was the first dual-core processor made by AMD. The AMD K10
was released in 2007 with a clock rate of 1.7GHz to 3.7GHz and multiple cores. The AMD K10 processors included the multi-core Phenom CPUs.
AMD merged with the graphics chip manufacturer ATI in 2006 and an initiative called AMD Fusion
was announced that merged a CPU (Central Processing Unit
) with a GPU (Graphics Processing Unit
) and 16 lane PCIe link which would eliminate the need for a northbridge chip. The new Fusion processor is referred to as an APU (Accelerated Processing Unit
In 2011, AMD released the Bulldozer
desktop processors which succeeded the AMD K10, and also the latest Bobcat
APU which was formerly called 'Fusion' and incorporates the GPU and PCIe link into the processor. The Jaguar core architecture
(2013) and later Puma architecture
became available in 2014.
A comprehensive list of AMD Processors can be found here.