Am5x86 - Citizendia

Am5x86-P75 for Socket 3

Am5x86-P75 surface mount

The Am5x86 processor is an x86-compatible CPU introduced in 1995 by AMD for use in 486-class computer systems. See also X86 assembly language The generic term x86 refers to the most commercially successful Instruction set architecture in the history of Personal The Intel 486, otherwise known as the 80486 i486 or just 486 was the first tightly pipelined X86 design A computer is a Machine that manipulates data according to a list of instructions. It was one of the fastest, and most universally-compatible upgrade paths for users of 486 systems.

Introduced in November 1995, the Am5x86 (also known as 5x86-133, Am5x86, X5-133, and sold under various 3rd-party labels such as "Turbochip") is an Enhanced Am486 processor with an internally-set multiplier of 4, allowing it to run at 133 MHz on systems without official support for clock-multiplied DX2 or DX4 486 processors. The Am486 is a 80486 -class family of Computer processors that was produced by AMD in the 1990s In Electronics and especially synchronous Digital circuits a clock signal is a signal used to coordinate the actions of two or more circuits The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. The Intel 's i486DX2 is a CPU produced by Intel that was introduced in 1989. The Intel IntelDX4 is a clock-tripled i486 Microprocessor with 16kb L1 cache Like all Enhanced Am486, the Am5x86 featured write-back L1 cache, and unlike all but a few, a generous 16 kibibytes rather than the more common 8 KiB. A kibibyte (a contraction of ki lo bi nary byte) is a unit of Information or Computer storage, established by the International A rare 150 MHz-rated part may have also been released by AMD.

Since having a clock multiplier of four was not part of the original Socket 3 design, AMD made the 5x86 accept a 2x setting from the motherboard and instead operate at a rate of 4x. When using an Am5x86, the motherboard must be set to the 2x setting. The chip will actually physically fit into an older 486 socket such as a socket 1 or 2 or the original 168-pin 80486 socket, but doing this requires a replacement voltage regulator, since the AMD chip runs at 3. 45 volts.

The combination of best-in-class clock speed and the relatively large 16 KiB write-back L1 cache allowed the 5x86 to equal or slightly exceed an Intel Pentium 75 MHz processor in integer arithmetic performance. The Pentium brand refers to Intel 's single-core x86 Microprocessor based on the P5 fifth-generation Microarchitecture. The integers (from the Latin integer, literally "untouched" hence "whole" the word entire comes from the same origin but via French Also, because it was based on a pure 486 design, it was compatible with older systems, something its slightly faster rival, the Cyrix Cx5x86, had trouble with. in August 1995, four months before the more famous Cyrix 6x86, the Cyrix 5x86 was one of the fastest CPUs ever produced for Socket 3 The CPU was commonly overclocked to 160 MHz, thereby giving performance similar to that of a Pentium 90 MHz system. Although it has been reported that individuals have successfully run the chip at 200 MHz, this would seldom have been achievable due to the rarity of VLB video cards and motherboards (especially the cache RAM) that could cope with a 50 MHz system bus. The VESA Local Bus (usually abbreviated to VL-Bus or VLB) was mostly used in personal computers A video card, also known as a graphics accelerator card, display adapter, or graphics card, is a hardware component whose function is to A motherboard is the central or primary Printed circuit board (PCB making up a complex electronic system such as a modern Computer or Laptop Static random access memory (SRAM is a type of Semiconductor memory where the word static indicates that unlike ''dynamic'' RAM (DRAM, it does not In Personal computers the Front Side Bus ( FSB) is the bus that carries data between the CPU and the northbridge. The image of the Socket 3 version above, of type ADZ, was in fact the preferred version of the chip because it was rated for higher temperatures and thus more forgiving of overclocking.

The Am5x86 is also notable for the first-ever use of the controversial PR rating. The PR ( P erformance R ating system was developed by AMD in the mid-1990s as a method of comparing their X86 processors to those of rival Because the 5x86 was the equal of a Pentium 75 MHz processor in benchmarks, AMD later marketed the chip as "Am5x86-P75".

Sales of the Am5x86 were an important source of revenue for AMD at a time when lengthy delays in bringing the AMD K5 to production were threatening the company's profitability. The K5 was AMD's first x86 processor developed entirely in-house introduced in March 1996

AMD manufactured the Am5x86 processor for ordinary PC systems until 1999. Year 1999 ( MCMXCIX) was a Common year starting on Friday (link will display full 1999 Gregorian calendar) It was popular for entry-level desktop systems, appeared in many different notebook models, and also sold separately as an upgrade processor for older 486 systems. Several companies made upgrade kits which packaged an AMD 5x86 with a voltage regulator and socket converter, which allowed its use on almost any 486 motherboard ever produced. The chips were even used on the Acorn RiscPC "PC card" second processors. The acorn is the nut of the Oak tree (genera Quercus, Lithocarpus and Cyclobalanopsis, in the The Risc PC (codenamed Medusa) was Acorn Computers 's next generation RISC OS / Acorn RISC Machine computer launched in 1994 The RiscPC's OpenBus only supported 32-bit processors, which meant that the Pentium could not be easily interfaced to it. The Pentium brand refers to Intel 's single-core x86 Microprocessor based on the P5 fifth-generation Microarchitecture. Intel's expensive Pentium Overdrive for 486 systems was a troublesome CPU, with many compatibility issues, and so was not used. The Pentium OverDrive was a Microprocessor marketing brand name used by Intel, to cover a variety of consumer upgrade products sold in the mid 1990s It The 5x86 therefore provided the acme of RiscPC Windows performance.

The chip remains in production today, and is a popular choice for use in embedded controllers. One derivative of the 5x86 family is the core used in the Élan SC520 family of microcontrollers marketed by AMD.

Models

Am5x86-P75 (X5-133)

350 nm CMOS process
L1 Cache: 16 KiB unified. Complementary metal–oxide–semiconductor ( CMOS) (pronounced "see-moss" siːmɔːs ˈsiːmɒs is a major class of Integrated circuits CMOS technology write-back or write-through. 4-way associative
Socket 3, 168-pin Socket 1, or Socket 2 with voltage regulator
Vcore: 3. Socket 3 was a type of CPU socket into which various X86 Microprocessors were inserted Socket 1 was the second of a series of standard sockets created by Intel into which various X86 Microprocessors were plugged Socket 2 was one of the series of sockets into which various X86 Microprocessors were plugged 45 V
Clock rate: 133 MHz
Front side bus: 33 MHz

External links

In Personal computers the Front Side Bus ( FSB) is the bus that carries data between the CPU and the northbridge.

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