Combined manual (knobs) and automatic control of fans

[epnina]

Hi all,

I've almost done assembling a new system (my first) and I'm left with the control type of fans dilema.

my MB supports PWM and can work with EasyTune6.

The thing is, I really would like to have a physical control over the fans as backup (not via a software but by knobs) should the automatic control fail (in TC the temperature sensor will "ware out" and in PWM maybe a bug or a virus...)

I wish someone could help me out with the following questions (or just with one), I'm really stuck with this:

1. Is it possible to have this sort of combined control over fans?

2. reffering to the CPU fan specificlly- is this fan always on and always on full speed (no control)? Or is it controlled seperatably than the case fans because of its importance?
I sortta understood that PWM means that when the CPU "feels" load it signals the case fans to start working, but what controls the CPU fan itself?

3. Does PWM control signal to all fans to work at once (noisy and not economic) , or it can signal a single fan?

4. I think TC's advantage over PWM is that each fan is controlled indepandently (has its own sensor that triggers it on), which is less noisy, more economic, and should one fan fail, the others kick in as backup. What do you think?

a lot of thanks in advance

 

[Ubrales]

Let's address your questions one at a time:

1. A 'combined' control is not possible; at least in a computer. With sophisticated software, it can be done in industrial applications. In a computer, it is "either/or" not both at the same time.

2. As you correctly observed, the CPU fan is critical for the cooling of the CPU. Yes, the temp sensor built into the CPU sends the signal to control the CPU fan speed. PWM stands for 'Pulse Width Modulation' is is an advanced means of precise speed control. The control is effected by varying the width of the input pulse to the fan. (Similar in principle to the control of YAG (and other) lasers). It is more precise. This feature is part of the energy suppyling the fan, and the fan must be capable of responding to PWM.

3. If your motherboard has PWM fan controls, it will supply PWM energy to all fan headers. However, the fans connected to these headers must be PWM fans to effectively utilize this speed control feature.

4. Yes, your assumption is correct! However the two are not mutually exclusive.

And of course, you can have certain fans independently controlled by a fan control device. Here is one: http://www.newegg.com/Product/Product.aspx?Item=N82E16811999171&cm_re=fan_speed_controller-_-11-999-171-_-Product