Jaton PowerPro VX, Руководство пользователя

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Chapter 2
12
Clock multiplier factor
The real operation clock within the CPU is the multiple of the external clock. We
refer to this factor as the clock multiplier factor. The four factors possible are 1.5,
2, 2.5 and 3. The factor differs from one CPU to another. For instance, the Intel
Pentium 166 CPU has a 66MHz external clock, with a multiplier factor of 2.5, so
that the speed of the internal clock is 66MHz x 2.5.
Internal clock
Also referred to as the real internal CPU clock, it is the actual internal operating
clock of the CPU. The Internal Clock is a multiple of the external clock and of the
clock multiplier factor. For instance, the Intel Pentium 90 CPU has a 60MHz
external clock and its clock multiplier factor is 1.5; the Intel Pentium P133 CPU
has a 66MHz external clock and its clock multiplier factor is 2.
Internal CPU clock = clock multiplier factor * external CPU clock
AT Bus clock
Also referred to as ISA SPEED, or AT CLOCK, or even ISA Bus clock. Ten years
ago, the original specification of AT Bus clock installed in the first generation
PC/AT computers was 8MHz, this means that there are some interface cards which
can only work at 8MHz. In order to guarantee compatibility with older hardware,
we still support 8MHz AT Bus clock, but if your interface card is newer or faster,
you can choose a higher speed for the AT Bus clock, in order to increase the
transmission rate of the interface cards. But we recommend you not to be too
ambitious. An 8MHz setup ensures maximum compatibility.
CPU Voltage - Vcore and Vio
From the voltage point of view, 586 series CPU can be divided into two categories:
Single Voltage CPU and Dual Voltage CPUs. Single voltage CPUs include: Intel
Pentium P54C series, AMD-K5 and Cyrix 6x86, etc.
Dual voltage CPUs include: Intel P55C with MMX, future AMD CPUs, Cyrix
6x86L and M2.
Dual voltage CPUs requires two different voltages for the power source: Core
Voltage (Vcore) and IO Voltage (Vio). Vcore provides all the power for internal
processing, and its power consumption is quite important. Vio provides the power
necessary for the external interface of the CPU.
P-Rating
The P-Rating is defined by some CPU manufacturers other than Intel to rate the
performance of their CPU in comparison with Intel Pentium CPUs. For instance,
Cyrix 6x86 P166+ has a higher actual speed compared with Intel Pentium P166,
and its internal clock need only be 133MHz versus 166MHz for Intel
’
s product.
The internal architecture is different between Cyrix 6x86 and Intel Pentium CPU
even they are treated as the same type.