The K6 microprocessor was launched by

AMD Advanced Micro Devices, Inc. (AMD) is an American multinational corporation and technology company headquartered in Santa Clara, California and maintains significant operations in Austin, Texas. AMD is a hardware and fabless company that de ...

in 1997. The main advantage of this particular microprocessor is that it was designed to fit into existing desktop designs for

Pentium Pentium is a series of x86 architecture-compatible microprocessors produced by Intel from 1993 to 2023. The Pentium (original), original Pentium was Intel's fifth generation processor, succeeding the i486; Pentium was Intel's flagship proce ...

-branded

CPUs A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary Processor (computing), processor in a given computer. Its electronic circuitry executes Instruction (computing), instructions ...

. It was marketed as a product that could perform as well as its

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

Pentium II The Pentium II is a brand of sixth-generation Intel x86 microprocessors based on the P6 (microarchitecture), P6 microarchitecture, introduced on May 7, 1997. It combined the ''P6'' microarchitecture seen on the Pentium Pro with the MMX (instruc ...

equivalent but at a significantly lower price. The K6 had a considerable impact on the PC market and presented Intel with serious competition.

Background

The AMD K6 is a

superscalar A superscalar processor (or multiple-issue processor) is a CPU that implements a form of parallelism called instruction-level parallelism within a single processor. In contrast to a scalar processor, which can execute at most one single in ...

-class

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

, manufactured by

, which superseded the K5. The AMD K6 is based on the Nx686 microprocessor that

NexGen NexGen, Inc. was a private semiconductor company based in Milpitas, California, that designed x86 microprocessors until it was purchased by AMD on January 16, 1996. NexGen was a fabless design house that designed its chips but relied on other c ...

was designing when it was acquired by AMD. Despite the name implying a design evolving from the K5, it is in fact a totally different design that was created by the NexGen team, including chief processor architect Greg Favor, and adapted after the AMD purchase. The K6 processor included a feedback dynamic instruction reordering mechanism, MMX instructions, and a floating-point unit (FPU). It was also made pin-compatible with Intel's Pentium, enabling it to be used in the widely available " Socket 7"-based motherboards. Like the AMD K5, Nx586, and Nx686 before it, the K6 translated x86 instructions on the fly into dynamic buffered sequences of

micro-operation In computer central processing units, micro-operations (also known as micro-ops or μops, historically also as micro-actions) are detailed low-level instructions used in some designs to implement complex machine instructions (sometimes termed ma ...

s. A later variation of the K6 CPU, K6-2, added

floating-point In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a Sign (mathematics), signed sequence of a fixed number of digits in some Radix, base) multiplied by an integer power of that ba ...

-based SIMD instructions, called 3DNow!. The K6 was originally launched in April 1997, running at speeds of 166 and 200 MHz. It was followed by a 233 MHz version later in 1997. Initially, the AMD K6 processors used a Pentium II-based

performance rating The PR (performance rating, P-rating, or Pentium rating) system was a figure of merit developed by AMD, Cyrix, IBM Microelectronics and SGS-Thomson in the mid-1990s as a method of comparing their x86 processors to those of rival Intel. The idea ...

(PR2) to designate their speed. The PR2 rating was dropped because the rated frequency of the processor was the same as the real frequency. The release of the 266 MHz version of this chip was not until the second quarter of 1998, when AMD was able to move to the 0.25-micrometre manufacturing process. The lower voltage and higher multiplier of the K6-266 meant that it was not fully compatible with some Socket 7 motherboards, similar to the later K6-2 processors. The final iteration of the K6 design was released in May 1998, running at 300 MHz. File:AMD K6 (Model6) 200ALYD ZS-PMax - Stack-DSC05068-DSC05133 (22382082681).jpg, A delidded AMD K6 processor File:AMD@350nm@K6@Model6 - (cpuid562)@AMD-K6-233APR@3.3V CORE C9743EJFW 1997 AMD DSCx8 polysilicon@macrolens.jpg, Die shot of an AMD K6-233APR processor

Features

* Seven execution units specialized in parallelized instructions * x86 decoders that translate x86 assembly to RISC86 instructions * IEEE 1149.1 boundary scan *

Speculative execution Speculative execution is an optimization (computer science), optimization technique where a computer system performs some task that may not be needed. Work is done before it is known whether it is actually needed, so as to prevent a delay that woul ...

optimization *

Out-of-order execution In computer engineering, out-of-order execution (or more formally dynamic execution) is an instruction scheduling paradigm used in high-performance central processing units to make use of instruction cycles that would otherwise be wasted. In t ...

Register renaming In computer architecture, register renaming is a technique that abstracts logical processor register, registers from physical registers. Every logical register has a set of physical registers associated with it. When a machine language instructio ...

Models

K6 (Model 6)

* 8.8 million transistors in 350 nm * L1-Cache: 32 + 32 KB (data + instructions) * MMX * Socket 7 *

Front-side bus The front-side bus (FSB) is a computer communication interface ( bus) that was often used in Intel-chip-based computers during the 1990s and 2000s. The EV6 bus served the same function for competing AMD CPUs. Both typically carry data between th ...

: 66 MHz * First release: April 2, 1997 * VCore: 2.9 V (166/200) 3.2/3.3 V (233) * Clockrate: 166, 200, 233 MHz

K6 "Little Foot" (Model 7)

* CPUID: family 5, model 7, stepping 0 * 8.8 million transistors in 250 nm * L1-Cache: 32 + 32 KB (data + instructions) * MMX * Socket 7 *

: 66 MHz * First release: January 6, 1998 * VCore: 2.2 V * Clockrate: 200, 233, 266, 300 MHz

Successor

The K6 line was updated with

SIMD Single instruction, multiple data (SIMD) is a type of parallel computer, parallel processing in Flynn's taxonomy. SIMD describes computers with multiple processing elements that perform the same operation on multiple data points simultaneousl ...

instructions (Branded as AMD 3DNow!) to create the K6-2 line of microprocessors.

References

External links

*
AMD K6, first of an impressive dynasty

{{AMD processors Computer-related introductions in 1997 K06 K06 Superscalar microprocessors X86 microarchitectures