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History Of AMD K6

AMD K6 Specification

AMD Architecture

AMD K6 Features

HISTORY OF AMD K6HISTORY OF AMD K6

1995-AMD K5 is too slow to compete with Intel’s fast Pentium CPU.

AMD launched its K6 processor to much acclaim amongst the computer world in 1997.

The K6 was built around the original NexGen 686 core which was inherited by AMD when it bought the small firm in 1996.

NexGen had developed a powerful "six issue" RISC processor core which gave the chip impressive sixth generation performance.

Additionally, they slap on Intel’s MMX code making it compatible with Pentiums.

These chips were compatible with HX, VX and TX chipset motherboards which supported MMX processors.

This placed it above Intel processors for many who did not wish to pay high prices for their processing power. 

 It was marketed as a product which could perform as well as its Intel Pentium II equivalent but at a significantly lower price.

 the AMD K6 processors used a Pentium II-based performance rating (PR2) to designate their speed. The PR2 rating was dropped because the rated frequency of the processor was the same as the real frequency.

First release: April 2,1997

AMD k6 is 32bit Processor.

Speeds of 166Mhz to 200Mhz can be maximize upto 300Mhz

8.8 million transistors in 350 nm.

L1-Cache: 32 + 32 KB (Data + Instructions)

MMX( Multiple Math eXtension, or Matrix Math eXtension.)

AMD k6 Microprocessor uses MMx Technology which consists of three improvements over the Non -MMX Pentium microprocessor:

1)57 new microprocessor instructions have been added that are designed to handle video, audio, and graphical data more efficiently.

2) A new process, Single Instruction Multiple Data ( SIMD ), makes it possible for one instruction to perform the same operation on multiple data items.

3) The memory cache on the microprocessor has increased to 32 thousand bytes, meaning fewer accesses to memory that is off the microprocessor.

Socket 7

Socket 7 is a physical and electrical specification for an x86-style CPU socket on a personal computer motherboard. In AMD k6 socket 7 is used insted of socket 5 used in intel p5 pentium microprocessor.

Major differences between Socket 5 and Socket 7 are that Socket 7 has an extra pin and is designed to provide dual split rail voltage, as opposed to Socket 5's single voltage.

Front side bus: 66 MHz

A front-side bus (FSB) is a computer communication interface (bus) often used in Intel-chip-based computers.

VCore: 2.9 V (166/200) 3.2/3.3 V (233)

Clockrate: 166, 200, 233 MHz

The AMD-K6 processor contains The AMD-K6 processor contains

• Parallel Decoders

• Scheduler/Instruction Control Unit

• Branch Logic

• Instruction Fetch and Decode

• Execution Units

Parallel DecodersParallel Decoders

• Short decoders - Decodes the most commonly used x86 instructions

• Long decoders - Decodes the semi-common and commonly used instructions

• Vector decoders - Decodes uncommon, complex x86 instructions.

Scheduler/Instruction Control UnitScheduler/Instruction Control Unit

• The centralized scheduler or buffer is managed by the Instruction Control Unit (ICU).

• The 24-operation buffer size is optimized for the efficient use of the processor's six-stage RISC86 pipeline and seven parallel execution units.

• The scheduler accepts up to four RISC86 operations at a time from the decoders.

• The ICU can simultaneously issue up to six RISC86 operations per clock to the execution units

Branch LogicBranch Logic

• The AMD-K6 processor uses dynamic branch logic to minimize delays due to the branch instructions common in x86 software.

• The processor implements a two-level branch prediction scheme based on an 8,192-entry branch history table, which stores prediction information used to predict conditional branches

• The branch target cache augments predicted branch performance by avoiding a one-clock cache fetch penalty.

• Load Unit - performs data memory reads with a two-stage pipeline; data is available from this unit after two clocks.

• Store Unit - performs data writes and register calculations with a two-stage pipeline; data memory and register writes from stores are available after one clock.

• Integer X Unit - operates on ALU operations, multiplies, divides, shifts, and rotates.

• Multimedia Unit - executes all MMX™ instructions.

• Integer Y Unit - operates on the basic word and double-word ALU operations.

• Floating-Point Unit - executes all floating-point instructions.

• Branch Unit - resolves conditional branches after they have been evaluated.

K6 was significantly cheaper than the Pentium

The AMD K6 processors used a Pentium II-based performance rating (PR2) to designate their speed

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

AMD K6 processor was faster than similar clocked K5 CPU in integer and floating-point calculations.

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