Me and Paul were having this discussion. (Quoted text is Paul's) But it seems
Paul is busy today... or maybe I made a complete fool of myself, but I still
don't understand. My question is at the very end of the text, but following
the discussion might help.
I would like to thank Paul for all the information he's provided so far.
---------------
> Cool N' Quiet is a feature of Athlon64 processors. When Windows
> is idle, the "CPU driver" can write a FID (frequency) control
> register, and drop the processor from 2400MHz, to 1000MHz. Since in many
interactive (web surfing, email) situations, the
> processor is idle most of the time, this saves electricity
> and makes the processor run cooler. It immediately speeds up
> as soon as you move the mouse.
It seems there's also a driver for Linux 2.6.10 and later kernels:
AMD Turion™ 64 Mobile Technology Processors,
AMD Opteron™ Processors, and
AMD Athlon™ 64 Processors Driver Version 1.60.01 for Linux 2.6. - Supports all
AMD Turion™ 64 Mobile Technology Processors, AMD Opteron™ Processors, and
Athlon™ 64 Processors released through 2006. Provides support for AMD
PowerNow!™ technology and, where appropriate, AMD’s Cool-n-Quiet™ technology
for Linux systems. Works with all kernels, version 2.6.10 or later. Requires
cpufreq-1.20, cpuspeed-1.20.1, or powersaved-0.8.19 or later to support SMP
and dual-core systems.
http://www.amd.com/us-en/Processors/...1_9706,00.html
So, the same processor may run at different wattages. OK.
> When the processor is running at full speed (say you are shrinking
> a DVD before writing a movie to a blank DVD), then the power difference
> between the high power and low power processors takes
> effect. Maybe if you kept your processor busy all the time,
> the lower power rated processor would give you a cooler running
> computer. But for interactive style usage, the Cool N' Quiet feature
> saves plenty of power.
I see... but I'm afraid I'll have a question below.
> As an example, look at PDF page 17 of this document. It shows the processor
> ADA3500DEP4AS, a 3500+.
>
>
><http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf>
>
> The allowed operating conditions, tested at the factory are:
>
> Name Power Frequency
> Max Pstate 89W 2200MHz
> Intermediate Pstate #1 69W 2000MHz
> Intermediate Pstate #2 50W 1800MHz
> Min Pstate 22W 1000MHz
Ok. Now, here's the SAME processor at:
http://www.amdcompare.com/us-en/desktop/default.aspx
Processor: AMD Athlon™ 64
Model Number: 3500+
Frequency (MHz): 2200
L2 Cache Size: 512KB
Socket: AM2
Stepping: F2
Manufacturing Tech (CMOS): 90nm SOI
Wattage (W):
System Bus (MHz): 2000
As you can see, there's nothing beside Wattage. At this stage, the choice is
between 35 or 62. Isn't this to operate at 2200 MHz, the maximum frequency?