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Fan Xpert 2: What can it do for you?

Level 13
Fan Xpert2: What can it do for you? Setting up fans, control your fans.

Asus Fan Xpert 2: A nice solution to control your Fans by using the Fan Xpert 2 Software, so it seems.
I have put it to the test. For the record: I do know there are separate fan controllers –and I use them to. However I always try to figure out the benefits of the options that are offered, like in Fan Xpert 2. I have worked with the previous versions as well. I also know about the stories that the 4-pins power fan headers on the Asus ROG boards are not using the power control function as they are developed by the industry. I believe that the Fan Xpert 2 controls the fan speeds by simply dropping the voltages that are directed to the fans (but correct me if I am wrong). Also, I am not going to explain how Fan Xpert 2 works here.

After having made those remarks, I do think Fan Xpert 2 has some real benefits.
For a product feature that is being advertised as one of its features for the Maximus and other Republic of Gamers series motherboards, the lack of complete and sufficient information is surprising.

If you are a buyer of one off these ROG products, you at least qualify as an PC enthusiast, right? So it should be possible to connect a cooling solution that goes far beyond 1 CPU fan, 1 Front Case Fan and 1 Back Case Fan.

The Cooling Solution I use is setup like this:

So the things that I was interested in – when setting up my build- where:

  • How many fans can I connect to each fan header? Why? Because most of the time those fan headers have a maximum power output; i.e. what is the maximum Wattage per connector.
  • Which fan headers are actually controlled by Fan Xpert 2?
  • Where do I put the RPM signal of my Water Cooling pump(s).
The manual has poor information on this subject:

  • It states that the CPU_FAN connector supports the maximum of 1 Ampere fan power.
  • The CPU_FAN and the CHA_FAN connectors support the FAN Xpert 2 feature.
According to an answer in another thread about the power, all fan headers are 1A. The formula for Watt = Volt x Ampere. So PSU supplies 12 Volt, therefor the total wattage per header is 12 Watt. I checked how much Watt the Fans are drawing, this can be found in the manufacturers specifications.

So it seems that 4 Fan headers can be controlled by the Fan Xpert 2 software, but this is not really true because the FANS connected to the CPU_OPT fan are “ mirrored” from the CPU_FAN header. So In fact we have 5 headers that can be used to connect FAN(s) groups to, that can be controlled by Fan Xpert 2

It would be useful to have the same fans, that are on the same location, to be connected to 1 fan header. So I will use y-splitters to connect more than 1 fan to each fan header. I get the following groups:

But what if I would like the software also to control the RPM from my Water cooling pump? This depends on the total amounts of Watts from the Pump. I decided not to connect the pump to the motherboard, because I use a separate-external controller/thermal sensor for the pump. I do this because the controller has a very loud speaker that signals if the pump should fail. Also I decided to connect the Front intake fan (group F) to the OPT_FAN1 the reason is that this Fan cannot slow down by decreasing its Volts (it stops running immediately). So it would not take any controllable Fan Header I switched it to the optional fans.

On the Maximus VI Extreme the following fan headers are available:
The total amount of wattage of the fan groups that I want to connect to each header does not exceed the 12 watts, so no problems there.

So I dug up the technical details for each fan:
I checked the minimum and maximum RPMs for each fan, as found in the specs, as stated by the BIOS (with no active BIOS fan profiles, so all at 100%) and as found by Fan XPERT 2.

Strange thing is going on when you look close at the stated RPM of fan group F1 and F2: both groups have the same fans: Noctua NF-F12 PWM fans that both are mounted as “pull” fans on a 360x120mm radiator (I use 2 of them). I connected group F1 to the CPU_FAN header and the BIOS and Fan Xpert 2 give a maximum speed of 1200 RPM, but they are rated for 1500 RPM! I connected fan group F2 to the CPU_OPT fan header (again the same Noctua fans are used), the BIOS gives a maximum speed of 1400 RPM and FAN Xpert 2 gives only 1200 RPM. If I switch FAN Xpert 2 to Full Speed …. The RPMs of the Noctua Fans on CPU_OPT read: 1425 RPM !! That’s strange.

Here you can see the maximum RPM stated by Fan Xpert 2

The CPU_FAN reads 1197 rpm and the CPU_OPT reads 1425 rpm, even though they are the exact same fans, the get different maximum speeds. I don’t know why and I am not going into discussions about that, I simply observe, make a note and get on with it.

After running the Fan Xpert 2 fan tuning program I get the following 4 Fan Profiles:

For fan group F1 and (since the CPU_OPT header is linked to this) also group F2

For fan group F3:

For Group F4:

For Group F5:
These are the fan speeds after tuning them, with the system pretty much Idling:


The difference is huge, not just in RPM but much more in the noise!!

I do not own the correct official equipment for measuring sound. I did use an app on my smartphone, that –as they state- should give some indication to the sound level.

The Sound level in my room (yes I live in a very small an quite town) with my PC turned off, no other machines running, no people etc. Just to establish a baseline is: 23 dB

Now the sound level with the PC switched on, everything (except the external radiator+5 fans) is enclosed in the case, like any normal user out there.


So with the tuning that Fan Xpert 2 did, the system produces 46 dB and when stressed maximum of 48 dB.

All tests are run with: Maximus VI Extreme, Core i7 4770K, Sapphire 7970, 8 GB Corsair Platinum, 2 x Intel 520 SSD in RAID0 (YES finally supporting TRIM). All mounted in a custom modded HAF X case, with complete high end custom water cool loop. For the test I have used these settings:
CPU overclocked@4400MHz, Dram overclocked to 2400MHz, GPU running in Oc mode 1050/1500 MHz. The CPU and GPU are watercooled! The influence off the tuning –and down scaling of the fan speed – by Fan Xpert 2 on the temperatures in the different parts of my PC will be shown a bit further down.

Now Let’s see what the sound level is when all fans run at 100% speed. It averages around 59 dB!


So the difference of running all fans on top speed or tuned by Fan Xpert 2 is 11 to 13 decibel.
For comparison: an normal conversation at a distance of 1 meter is something like 70 dB of sound, the sound of a bussy street is about 80dB. That is around the same difference in noise level!

To see what the temperatures do when the fans are either tuned by Fan Xpert 2 or running at full speed (100%), a ran a number of tests:

  • System Idle
  • Playing a round off Battlefield 4 Multi play for at least 30 minutes
  • Run AIDA64 system stability test for at least 30 minutes
  • Run 3DMARK Firestrike Extreme in Timed loop
  • Run 3DMARK Vantage, performance level, 3 loops
The results are shown in this graph:

This shows that the temperatures of the CPU, GPU and the motherboard are slightly lower when all fans run at full speed. In my opinion the difference is so small, that it justifies using the fan profiles created by Fan Xpert 2.

The final cooling setup that I ended up with looks like this:

Conclusion: Fan Xpert 2 is a good tuning tool for your fans, although it doesn’t seem to take full advantage off the possibilities of true 4-pins fan controller. You can easily setup your system and have the software control a large amount of fans. In my situation it controls a total of 11 Fans! The total noise level drops significantly, the negative effect on the temperatures is only a small (varying from 1 to 5 degrees Celsius).

I thought this is reason enough to share with you all!

Level 9

Never set radiator on top! in front for cool air and out of top and back with hot air fact.