2024年3月14日发(作者：)

Pentium 4-M

Pentium 4 HT

Pentium D

Pentium Extreme Edition

Pentium M

Core Solo

Core Duo

Core 2 Solo

Core 2 Duo

Core 2 Quad

Core 2 Extreme

Atom

Celeron

Celeron D

Celeron M

Celeron Dual-Core

Pentium Dual-Core

Pentium Pro

Pentium II Xeon

Pentium III Xeon

Xeon

Itanium

Itanium 2

100 MHz4

133 MHz-200 MHz4

133 MHz-200 MHz4

200 MHz-266 MHz4

100 MHz-133 MHz4

133 MHz-166 MHz4

133 MHz-166 MHz4

133 MHz-200 MHz4

133 MHz-333 MHz4

266 MHz-333 MHz4

200 MHz-400 MHz4

133 MHz-166 MHz4

66 MHz-266 MHz1-4

133 MHz4

100 MHz-200 MHz4

133 MHz-200 MHz4

133 MHz-266 MHz4

60 MHz-66 MHz

100 MHz

1

1

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

3200 MB/s

4256 MB/s-6400 MB/s

6400 MB/s-8512 MB/s

4256 MB/s-6400 MB/s

6400 MB/s-8512 MB/s

3200 MB/s-4256 MB/s

4256 MB/s-5312 MB/s

4256 MB/s-5312 MB/s

4256 MB/s-6400 MB/s

4256 MB/s-10656 MB/s

8512 MB/s-10656 MB/s

6400 MB/s-12800 MB/s

4256 MB/s-5312 MB/s

528 MB/s-8512 MB/s

4256 MB/s

3200 MB/s-6400 MB/s

4256 MB/s-6400 MB/s

4256 MB/s-8512 MB/s

480 MB/s-528 MB/s

800 MB/s

800 MB/s-1064 MB/s

3200 MB/s-12800 MB/s

800 MB/s-1064 MB/s

3200 MB/s-5312 MB/s

[]

Pentium 4 HT Extreme Edition200 MHz-266 MHz4

100 MHz-133 MHz1

100 MHz-400 MHz4

100 MHz-133 MHz1

100 MHz-166 MHz4

AMD processors

CPU

K5

K6

K6-II

K6-III

Athlon

Athlon XP

Athlon XP-M

Duron

Sempron

Athlon MP

FSB Clock

50 MHz-66 MHz

66 MHz

Number of CyclesBus Width

1

1

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

64-bit

Transfer Rate

400 MB/s-528 MB/s

528 MB/s

528 MB/s-800 MB/s

528 MB/s-800 MB/s

1600 MB/s-2128 MB/s

1600 MB/s-3200 MB/s

1600 MB/s

1600 MB/s-2128 MB/s

1600 MB/s-2128 MB/s

2656 MB/s-3200 MB/s

1600 MB/s-2128 MB/s

66 MHz-100 MHz1

66 MHz-100 MHz1

100 MHz-133 MHz2

100 MHz-200 MHz2

2

100 MHz-133 MHz2

100 MHz-133 MHz2

166 MHz-200 MHz2

100 MHz-133 MHz2

Mobile Athlon 4100 MHz

Vital Statistics

Warning: This is a confusing collection of numbers. What is important is how the different numbers relate to each other. Specific numbers

are plugged in because they are occasionally mentioned in the literature.

Example: There are two versions of the Intel 2.4 GHz Pentium 4. One get a clock speed from the mainboard of 100 MHz, but

since it transfers data 4 times per clock tick its "Font Side Bus" (FSB) to memory and I/O is said to be four times the clock or 400

MHz. Internally the CPU has a "multiplier" of 24, meaning the external clock is divided into 24 periods to produce the 2.4 GHz

value. A slightly more modern version of P4 gets a 133 MHz clock, has a 533 MHz Front Side Bus and has a multiplier of 18.

The equivalent AMD Athlon XP 2400+ gets a clock of 133 MHz, has a Front Side Bus twice that at 266 MHz, and an internal

multiplier of 15. That gives it an internal speed of 2.0 GHz, but since it executes more instructions per internal clock tick it is

rated to be equivalent to Intel's 2.4 GHz.

Chip Type

Pentium 4 2.4

Pentium 4 2.4A

Athlon XP 2400

Actual ClockBits/ClockFSBMultiplierSpeed

100 MHz4400 MHz242.4 GHz

133 MHz4533 MHz182.4 GHz

133 MHz2266 MHz152.0 GHz

The earliest PC had one clock, and its signal applied to the CPU, memory, and all the I/O devices. A modern PC has many different clock

signals for different areas of the machine. Clocks are generated by the mainboard. Their speed is often set in the BIOS setup panels that

appear when the user presses DEL or another key during the power up boot.

CPU socket clock

The mainboard generates a clock signal that paces the transfer of data to and from the CPU. Data from the CPU may be going to

memory, to the AGP video card, or to an I/O device. The mainboard may sense the CPU chip and set the clock based on the

manufacturer's recommendation, or it may provide a BIOS setup panel that lets the user adjust the clock value. The standard values

tend to be 100, 133, 166, or 200 MHz.

Front Side Bus (FSB)

The CPU transfers data to the "Northbridge" chip on the mainboard. From there it can go to memory, the video card, or the I/O bus. An

Intel CPU transfers data 4 times for every cycle of the CPU socket clock. So while the actual clock speed may be 200 MHz, an Intel

CPU chip is typically described as having an 800 MHz Front Side Bus. AMD is more complicated. The old 32 bit Athlon processors

transferred data only twice per clock cycle. With a CPU clock of 166 MHz, the FSB is 333 MHz. However, the new Athlon 64 CPU

chip has its own integrated memory controller and a high speed HyperTransport integrated I/O bus. FSB numbers would be

meaningless. There is no Northbridge chip between the CPU and other devices. The CPU can use its direct connection to memory

while at the same time performing high speed I/O to video or other devices.

Multiplier

The CPU generates an internal clock that runs faster than the mainboard clock. If the mainboard clock is 100 MHz and the CPU

"multiplier" is 24, then the internal clock cycles 24 times for every tick of the mainboard clock, producing a CPU speed of 2.4 GHz.

The same 2.4 GHz can also be produced by applying a multiplier of 18 to a mainboard clock running at 133 MHz. The multiplier is

manufactured into the CPU chip and cannot be changed.

Memory

Modern mainboards generate a separate clock to the memory. As it happens, the current memory clock rates are also 100, 133, 166,

and 200 MHz. Some motherboards generate this clock as a completely independent number, while others express it as a ratio to the

CPU bus clock. DDR (double data rate) memory transfers data twice per cycle (on the tick and again on the tock) and is therefore

often quoted as having a speed that is twice the actual clock speed (200, 266, 333, or 400 MHz).

PCI Bus

The PCI standard calls for a 33 MHz clock speed. Some systems generate this independently, but most systems simply divide the

100 MHz CPU bus clock by three or the 133 MHz clock by 4. This is fine as long as you stick to the standard values. If you use the

BIOS to nudge the CPU up slightly to a non-standard value like 110 MHz, then the PCI bus will also be running fast. At some point,

one of the adapter cards will be far enough out of spec that it will become unreliable.

The Front Side Bus connects the CPU to memory. If the FSB is running at an effective rate of 800 MHz but the fastest memory is 400 MHz,

then the CPU gets no benefit from its data transfer ability. The newest high performance mainboards have two separate memory buses.

DDR memory has to be installed in pairs. A memory reference is split between the two 400 MHz buses producing an 800 MHz aggregate

transfer rate that matches the speed of the CPU.