AMD 64 Quiet N Cool ?

[NapalmDeath]

I thought the AMD 64 Quiet N Cool was:

Cool N Quiet turns down your CPU voltage and core speed so that your fan can run slower and is therefore quieter when you're not doing CPU intensive tasks.

They even give you a small software applet that shows your FSB and VCore. I have a Venice 3200+, so my FSB is 2,000, and VCore is 1.78.

After enabling Quiet N Cool:

1) Download and install the AMD Athlon™ 64 Processor Driver for Windows XP and Windows Server
2003 Version (exe) 1.2.2.2

2) Enable Cool'n'Quiet in your BIOS

3) Enable ACPI 2.0 support in your BIOS (if this option is available). Some motherboards have built-in
support for APCI 2.0 and offer no option to control it in their BIOS.

4) Set the power management to "Minimum power management" in Windows.

I noticed the FSB and VCore never changed when idle.
I sent a technical request to Asus about it, and their response was:

Dear Sir,

The Cool N Quiet feature of the CPU is for controlling the CPU Fan speed according to the load of the CPU. This feature does not adjust the FSB or VCore of the CPU.

I responded with "No, that's the Q-Fan feature, and not AMD Quiet N Cool.


Who's right?

[luggage]

You are.

[Slaugh]

You are right! Cool'n'Quiet dynamically changes the voltage and the multiplier of your CPU. My Athlon 64 is idling at 1 GHz with 1.1 V (2.4 GHz, 1.5 V max). QFan is disabled in my BIOS, as well as the CPU fan monitoring, because I'm not using a fan on my CPU but a waterblock. QFan controls the CPU fan speed according to the CPU temperature, and because your temperature is reduced at lower CPU speed, QFan is supposed to slow down the fan (or completely stop it on certain boards).

Cool'n'Quiet technology works by reducing a system's clock speed and processor voltage when full processing power is not required. This reduces the demand on the power supply unit and allows the processor to run cooler and use a heatsink with a quieter fan.

Source: http://www.amd.com/us-en/Processors/Com ... 39,00.html

Here's a snapshot of AsusProbe before and after launching the ATI's Double Cross technology demo on my computer (Athlon 64 3400+ on a Asus K8N-E deluxe board). You can easily see that the Vcore is changing during the demo:

[=assassin=]

and VCore is 1.78.

1.78?!!! Is that a spelling mistake or are you really running it that high??

[vapb400]

yea 1.78 is waaaay to high.

[Mats]

yea 1.78 is waaaay to high.

Yeah, that CPU is going to die a napalm death...

And you're mixing up bus speed (FSB, HTT, tunnel speed or whatever) and clock speed.

[NapalmDeath]

yah, it's a typo.

Freq: 2,000
VCore 1.400

The QnC not working is a bios issue.
I'm on 403, and a few folks have managed to download a 502 beta that Asus keeps pulling down from their ftp.

The USB rear port hasnt dropped on me lately, and the buzzing sound from the coils is only noticeable in dead silence.

[m0002a]

You need to check the User Manual for your motherboard to determine if it supports Cool'n'Quiet. Your vcore should go from 1.4 to 1.1 at idle if it is working. It works great on my A8N-E, but not all motherboards support it.

[NapalmDeath]

It's working now with BIOS update 506.

tks!