How to set fan curves?

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mokodi
Posts: 6
Joined: Thu May 26, 2016 7:27 pm

How to set fan curves?

Post by mokodi » Thu May 26, 2016 7:37 pm

Hey everyone I'm building a new Skylake system soon with the following specs:

-Core i7 6700k
-Asus Z170-A
-16 GB DDR 2400
-Asus GTX 970 STRIX
-Fractal Design R4 (reused)
-2x Stock Fractal Fans
-Scythe Cooler with Noctua NF-A15
-Seasonic 460 watt fanless

My old system was pretty quiet but I used a Gigabyte motherboard with poor fan controls. I just undervolted my fans instead of using the bios to control it based on temperature. I bought the Asus motherboard because I've heard good things about the fan control and want to fully utilize the functionality.

From what I've read I should go into the bios and run the Q-tuning ability to get the min and max speeds of each fan and then adjust the curves. How should I adjust the curves to get it as quiet as possible? The SPCR 4k guide shows the fan curve set flat all the way and jumping to max at 75C

Image

Is this for the case fan? Won't it be better to set a gentler sloping curve rather than jumping to 100% at 75C?

How should the CPU fan curve be set up?

Abula
Posts: 3616
Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: How to set fan curves?

Post by Abula » Thu May 26, 2016 8:57 pm

Welcome to SPCR mokodi
mokodi wrote:Is this for the case fan?
Well you need to see which fans you connected to each, In the middle of the screen you will see a lot of dots, if you click on each it will change and show the settings for each fan, you need to know which you connected to each header, stock they stay CPU_FAN1, CHA_FAN1, CHA_FAN2, CHA_FAN3, OPT_FAN1, OPT_FAN2, OPT_FAN3, you can rename them, i think you already did as it displays phanteks on the top left.

Have you ran the tuning? i think you did as you already have a graph, but usually the suggested graph post running the tuning is not like that. Run the tuning again to see if its going as low as it can on each fan. Also enter the bios and check that CHA_FAN1 is set to either PWM or DC (if you are fans are 4pin use PWM, if your fans are 3pin use DC), make sure each fan is setup correctly in the bios.

Now the graph its up to you, at the moment you practically have it set to two speeds, i would use the breakpoints to have a more steady rising, for example i would drag the first breakpoint for 390rpms until 50C,, then the second breakpoint i would use 60C / 760rpms, and leave the last breakpoint as it shows the graph. Then test, run stress test and the usual day to day basis, from browsing to gaming, idk really what you do with it, but start monitoring how the fans behave and see how you like it, adjust the graphs according to your cooling needs and desires of noise, this is more something personal than whats the best, only you can decide what will you sacrifice in terms of temperature for a quieter setup.

CA_Steve
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Joined: Thu Oct 06, 2005 4:36 am
Location: St. Louis, MO

Re: How to set fan curves?

Post by CA_Steve » Thu May 26, 2016 8:58 pm

Welcome to SPCR.

Hey - if you haven't bought the gfx card yet, the GTX 1070 with aftermarket coolers should be out in a month or two.

fan curves: there's a couple of approaches you can take. Some people like to continuously ramp up the fan rpm with temp. I like to distinct setpoints of flat, shallow ramp, steeper ramp, then "holy hanna, there's a fire in them there hills" for the CPU fan and flat, followed by steep ramp for the case fans. So, for most of the operating range I never hear fans ramping up and down.

For case fans, I listen and determine when I can't hear them over the other fans and use that for the flat range. Then around 50C case temp or 70C CPU temp, go for a steep ramp.

The CPU can have abrupt changes in temp as it loads and unloads. So, you want to mess around with your particular use cases, but stay away from steep ramps until it gets toward the toasty end of the range. Otherwise you'll hear the CPU fan ping ponging up and down in rpm. The Asus boards DO have hysterhesis settings - definately play with those to slow down the pingponging.

mokodi
Posts: 6
Joined: Thu May 26, 2016 7:27 pm

Re: How to set fan curves?

Post by mokodi » Fri May 27, 2016 1:17 pm

I have all the parts except for the motherboard and CPU right now which are on the way. Sorry I wasn't clear but the picture I posted is actually from SPCR's 4k gaming build guide. I was thinking of a gentle ramp up with the fans as well but I was confused when I saw the guide so I ended up posting here looking for feedback on what the best practices are. Based on your responses I guess it's a matter of experimenting and trying things out. My uses for the computer will be browsing, programming, and gaming. I'll have headphones on for gaming so it's ok to have a bit of noise then.

I will update you guys once I have all the parts and have the system up and running.

Abula
Posts: 3616
Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: How to set fan curves?

Post by Abula » Fri May 27, 2016 4:46 pm

Try if you can to share your thoughts, and if you have the time, some pics.

Good luck with your setup,

If you need more help once you build, post it.

mokodi
Posts: 6
Joined: Thu May 26, 2016 7:27 pm

Re: How to set fan curves?

Post by mokodi » Mon Jun 06, 2016 9:26 pm

I am still in the process of setting everything up but I just wanted to report on the bios settings. I updated the bios to the latest version which is 1801 and I'm happy to report that the Q-Fan tuning works fine. The bios detected a min of 18% for my Noctua NF-A15 and around 40% for the Corsair AF140 and stock Fractal 140mm fans.

During idle the Noctua is able to reach speeds of ~220 RPM at 18%.

I know there were concerns with bios updates causing min duty to be very high for Q-fan tuning but at least on this board it is still safe. It's a bit disappointing that some advanced options available in FanXpert is not present in the bios. For example you cannot set a delay on the spin up and spin down timer.

The ramp up is also a bit strange to me. I ran Prime 95 with 4 threads blended and Hardware Monitor reported temps of 80+ on each core. However the fans don't ramp up all the way except in certain situations where temps exceed 85+. According to the fan curve set in the bios they should ramp up to 100% past 75C.

There is also a fan stop feature for the chasis fans which allows you to stop the fans completely at lower temperatures. It seems to work but I have left fans to run all the time because when set at 40C I noticed the fans would cycle periodically at low loads. It turned on 2-3 times per minute for a short while when the CPU temperature crossed the threshold. Since the case fans at minimum are lower than the noise floor I'll keep it running all the time because I think constantly stopping and starting the fan may not be good for the life of the fan.

mokodi
Posts: 6
Joined: Thu May 26, 2016 7:27 pm

Re: How to set fan curves?

Post by mokodi » Tue Jun 07, 2016 10:14 am

Another thing I noticed is that enabling XMP will also multi core enhancement which overclocks the processor by 200 MHz and increases the vcore from 1.29v under load to 1.39v. The side effect is much higher temperatures. I've left it disabled for now because I think you can get better results with manual overclocks. Such a slight increase in core clocks should not need any additional voltage

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