HP Vectra VL 5/xxx 5 manual Devices on the Processor-Local Bus, Intel Pentium Microprocessor

2 System Board

Devices on the Processor-Local Bus

	Devices on the Processor-Local Bus
	The Intel Pentium Microprocessor
	The Pentium processor is packaged in a pin-grid-array(PGA), and is
	seated on the system board in a zero-insertion-force(ZIF) socket 7. Only
	upgrades that are pin compatible with the original processor, manufactured
	by Intel, are supported.
	P54CS chips working at 133 and 150 MHz (along with P54C chips working at
	75, 90, 100 MHz and new versions of the 120 MHz chip) require a 3.3 V
	supply. A passive shorting block is sufficient to connect the regulated 3.3 V
	output of the power supply directly to the Pentium processor.
	P54CS chips working at 166 and 200 MHz require between 3.45 and 3.60 V.
	They need an VRE voltage regulator module (VRM), in which the voltage
	is actively derived from the 3.3 V, 5 V and 0 V outlets of the power supply.
	P55C chips, with MMX technology, require two voltage supplies: 3.3 V for
	the input and output buffers, and 2.8 V for the core logic. It requires an
	active VRM that is specifically designed for use with the MMX processor.
	This VRM can be identified by the inscription “2.8 V” marked on the board.
	Any thermal contact material between the processor and the heat-sink must
	not be removed or disturbed. The cooling needs of the processor are critical.
MMX Technology	The instruction set of the MMX processor includes 57 new instructions, four
	new 64-bit data formats (depicted below) and eight new 64-bit MMX
	registers. As well as the pipelined parallelism of the traditional Pentium
	architecture, MMX is capable of SIMD parallelism (single-instruction/
	multiple-data). Instead of combining a pair of operands to produce a single
	result, each instruction is able to gang each operation over a large number of
	pairs of operands, so producing a large number of results concurrently. This
	type of parallelism is particularly useful when processing large vectors and
	arrays of data (in graphics and audio processing, for example).

Quadword

64 bit

Packed double word

32 bit

32 bit

Packed word

16 bit

16 bit

16 bit

16 bit

Packed byte

8 bit

8 bit

8 bit

8 bit

8 bit

8 bit

8 bit

8 bit

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