Asus P7P55D-E LX and Noctua NH-D14

[nextlcder]

I need some help cuz I'm gonna build a new pc including these two components: an Asus P55 mobo and the famous Noctua NH-D14 fan to cool a Core i5.
As those Noctua cpu coolers (3-pin connector) doesn't support the PWM function that has the 4-pin connector in the motherboard, I'd like to know if the mobo will be able to control the NH-D14 fan speed automatically, based on the cpu load and temperature, so that it doesn't matter if I choose either a PWM or non-PWM cooler. Or will it work at full speed all the time, no matter what I do?
In the FAQ for this fan model at the Noctua website, it says that you can connect the non-PWM 3-pin fan to the 4-pin connector in some mobos and they are automatically regulated, but I guess that's not in all mobos. Do Asus mobos support this?
What are the advantatges of PWM fans if they supposedly can be regulated automatically by voltage as well?

Thanks

 

[BillParrish]

The answer to your question is "yes".

Yes, you will have auto fan speed adjustment based on CPU temp even with a 3 pin fan, it will just be the old style of doing it. Works fine and is intended for your situation with a 3 pin fan.

Yes, you will also have the option to run either a 3 pin or 4 pin fan 100% all the time if you want to.

I am sure your new ASUS board will do this. But see below, consider reading the manual for your board while you are chillin.

PWM fans can have their speed adjusted by the motherboard in much more fine increments and more accurately. Its all a balance of fan speed (Noise !! ) vs CPU temp (Load !) with the goal being to run the fan just fast enough to keep the CPU at an acceptable operating temp. Keep in mind Intel engineers goal is to reduce noise, they are not interested in OCing or bragging rights for temps when they design this stuff so the fully automatic PWM fan control (see below and EIST) will let the CPU run warmer than most of us here are used to seeing so they can keep the fan noise as low as possible. And since 99% of PC;s in the world are in offices that makes sense.



You can download the manual from Asus to double check me (should do it anyway if thinking of buying the board and grab the latest sound and LAN drivers while you are there).

There will be a setting in the bios for CPU fan control or words to that effect with a couple of different setting options. I am used to Gigabyteme boards so I will be using there terms but I am 99.32% positive the Asus will have the exact same thing with just slightly different words/description but the way it will work is the same. And the Asus may have a variation I don't mention, thus - download the manual. If you intend to OC you need to know the bios settings inside out anyway.

CPU fan control options:

Disabled : This turns off all CPU fan control and your fan spins 100% all the time, 3 pin, 4 pin does not matter you get all the fan all the time. Basically locks the cpu fan header to put out 12V all the time, end of story.

Legacy (also called Voltage control):
intended for your situation with 3 pin fan but will work with 4 pin fan too. The board has a thermal sensor mounted under the CPU socket that monitors the CPU temp and adjusts the voltage going to the fan header based on temp (or load - same thing really) this is the older automatic fan speed control and will work with any fan. It is not as accurate as newer methods in optimizing fan speed vs temp and because of the on the board sensor has a slower reaction time to changes in CPU temp. Usually there is a voltage vs temp table of values stored in the bios that are used to determine at what temp should be what fan voltage so speed "jumps" in steps based on lookup table values. So the voltage going to the fan is changed in steps. This works well and for many years its all there was and the world was happy. You can think of this as like having a speed control knob with "click stops" very slow, slow, low, medium, fast, high, full blast, etc. like a selector switch with 10 or so selections.

PWM fan control:
4 pin only. Latest and the greatest if done properly. Allows very fine/small speed adjustments over a wider range of fan speed, fan always gets 12V but its speed is controlled by an electronic pulse on the 4th pin read by the fan. This pulse can adjust the fan speed exactly and in very small increments. You can think of this like a volume control, infinitely adjustable, from barely moving to full speed and you can set it almost exactly anywhere in-between you want.

PWM + EIST (Enhanced Intel Speed ) The CPU itself provide instant temp updates to the motherboard and fan speed is also almost instantly set to keep the CPU within an acceptable operating temp while running the fan as slowly as possible to maintain the balance of noise vs temp. Some other things too but thats the gist of it, newest most accurate and fastest adjusting method of keeping fan running as quietly as possible over all load conditions.

Intel.com has enough info to make your head explode. Use the search box.

Anyway you are buying a new generation board from a top tier manufacturer. You will be fine, it will all be in the bios. Read the manual.