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a while ago (maybe up to a month or two) i was reading about a motherboard that had semi fanless capabilities like some gpu's that switch fans completely off under a certain temperature and it is exactly what im looking after for my semi gaming htpc

the problem is i cant find any more information on this, i KNOW i saw it but i cant find the article (i think i read about it on TR but not 100% sure) i was thinking everyone would be releasing these like what happened with the gpu's but nope all motherboards i have been looking at dont have the feature

i dont even care what cpu its for (amd or intel) or pretty much anything else about it - its currently the most important feature i want for my htpc upgrade

anyone know what motherboards have semi fanless controls?

Not sure what you mean. Are you looking for a way to turn the CPU fan off when the system is under moderate load? Unfortunately, that is probably going to require a large CPU cooler (problematic with smaller HTPC cases) and/or a lot of air movement through the case (which kind of defeats the point of making the GPU and CPU fanless in the first place).

I've read about special cases which are designed to passively cool the CPU (the outside of the case is used as a heatsink and coupled to the CPU via heatpipes), but they tend to be bulky (since a lot of surface area is required), and expensive (since they tend to be all aluminum, and are a low-volume niche product).

yes they turn off during low load (movie watching in particular)
my cpu is cool enough while watching movies that even the crappy intel cooler is on the lowest rpm the motherboard can output so my cm hyper212 plus could easily handle it - and as a test i stopped the fan while watching a movie and it was fine

i know they exist as i saw one with it and got excited thinking everyone would be releasing them just like what happened with the same feature on graphics cards

Don't know anything that goes to 0 RPM / 0 dB, but would e.g. the Mugen 5 PCGH at 4-14.5 dB do?

Obviously you might need the case and room cooling to be helping out.

If your motherboard offers fan control you can always set a custom fan profile that keeps the fan off until a certain threshold is reached.

I agree, I think the BIOS-level fan controls on Asus/Gigabyte/AsRock boards would do what you need. Most PWM fans don't actually spin once the PWM signal is below....20%(?) so it would just be a matter of satisfying that setting. Of course, setting a PWM signal on that's below the fan's threshold could result in unwanted PWM whine that could be worse than running the fan at minimum RPM, so 0% is ideal.

No guarantees, my mobos are too old to have the level of fan control granularity that today's mobos offer. But anyone with a recent board should be able to test it and report in.

Waco wrote:

If your motherboard offers fan control you can always set a custom fan profile that keeps the fan off until a certain threshold is reached.

IIRC none of my motherboards let you set the PWM duty cycle to 0%, and newer fans tend to be pretty accurate about scaling RPMs to PWM duty cycle (so if you set 20%, you will get approximately 20% of max RPMs).

Seems odd that laptops are the only ones allowed to run with their tiny CPU cooling fan off/passive.

Shoot, on my HTPC, I throttle my A8-5600K all the way back to 1.8GHz hard upper limit when it's doing anything besides gaming or encoding to reduce fan noise and power consumption. I believe that trims it down to about 35-40W system power consumption (don't have a Watt meter).

DPete27 wrote:

Seems odd that laptops are the only ones allowed to run with their tiny CPU cooling fan off/passive.

Don't the ones that do that tend to thermally couple the CPU to the outer casimg via a heatpipe?

The heatpipe designs typically just transfer the heat from the CPU to the heatsink fins mounted on the exhaust of the fan. I think heatpipes are more common these days with thinner laptops not being able to stack the mobo+CPU+heatsink on top of each other. When you don't have to put the fan on top of the CPU, the fan/heatsink can be the full thickness of the chassis.

There's always NOFAN for the adventurous.

just brew it! wrote:

Waco wrote:

If your motherboard offers fan control you can always set a custom fan profile that keeps the fan off until a certain threshold is reached.

IIRC none of my motherboards let you set the PWM duty cycle to 0%, and newer fans tend to be pretty accurate about scaling RPMs to PWM duty cycle (so if you set 20%, you will get approximately 20% of max RPMs).

Really? I recall my Gigabyte board letting me set 0%, but this was in the Z68 days using their crappy Easy Tune software (the controls in the BIOS were pretty sparse).

I haven't checked on recent boards, I just assumed that was a common feature. I should stop assuming that things that make sense are included. RGB control is far more important.

Topinio wrote:

There's always NOFAN for the adventurous.

If nothing else those sinks are pretty.

I'm pretty sure this was about an AIO water cooler. I'll see if I can dig it up.

fwiw I could be totally wrong, but it rings a bell.

I wouldn't fret about trying to find a fan/board combination that will stop the fan below a certain threshold.

Human hearing isn't linear, and fan noise isn't linear. The result is that a very low-RPM fan (500rpm for example) will be as good as silent whilst still providing a significant cooling upgrade over passive cooling only.

We're talking "so quiet that the noise of your own blood pumping through vessels near your eardrum" will register louder than the fan from a distance of more than two feet or so.

You don't need silent, you need inaudible and that's both more efficient and also easier to achieve.

Chrispers is obviously right. I have 2 fans on an AIO, and two other fans in my case. They all run at such RPM that I can't hear my case above the ambient noise of the home. It's awesome.

FWIW that amounts to ~900 RPM on the AIO and ~800-1000 RPM on the case depending on the temps. It's great.

I'm terribly late seeing this, but ASRock fan controls go to 0%, which has the effect you're looking for. Certain fans ignore PWM signals below some threshold, but most cut to zero below 20-30% on PWM or 40-50% on voltage control. I would not recommend setting an AMD system up this way, since most of their fan controls seem to be based on slow temperature sensors (it'll take a bit for the fan to turn on). Intel + ASRock is plenty responsive, and I ran one that way for a while.

My Gigabyte Z370 HD3P allows me to turn off the CPU fan when the temperature is below a threshold that I specify. I only use the feature with the case fan since my CPU fan is very quiet and practically inaudible outside the chassis, but if I had a low TDP CPU in a HTPC it would make sense to use that feature. I guess you'd probably like a smaller (micro ATX?) motherboard, but I would expect that Gigabyte and others would also have that feature on their smaller MBs. I built a PC at work with an ASUS Prime X399-A motherboard and it also allows me to turn off any fans if I want to, although this is not usually what I would expect would matter most to people building Threadripper systems.

My i7-8700k isn't exactly a first choice for building a fanless PC, but there are plenty of much lower TDP CPUs that you can choose for your HTPC. If it only needs to be used for video playback and perhaps Steam streaming, then you don't require much CPU power. If I were to build a very quiet PC, I'd probably consider a Ryzen APU based system as it seems to offer a good compromise between performance and power consumption (and price is also nice).

woohoo thanks guys i knew that i saw semi fanless motherboards somewhere and its exactly what i want to go with my semi fanless psu and gpu
i know good quiet fans are effectively zero rpm but im looking to build something new anyways and this way i can use my high performance high rpm fans i already have and it will be totally quiet when im just watching tv/movies
most of the really quiet fans dont go very high rpm and thus not giving me the cooling i need for when everything is overclocked and playing games

I wouldn't disregard fans at all... I've found that anything under 2000RPM will be pretty noiseless (MBP at 53C runs like a champ) and won't be annoying... but then again that depends on the fan. Also, any new motherboard will shut down their fans if they're not needed (tested two Asus Ryzen mobos that have that feature). With that being said, if you're truly looking for the silent experience, I may recommend you something built by DIY Perks: https://www.youtube.com/watch?v=RZoX7glIAS4

And I just read that you're overclocking - you may want to go for a water cooling solution in that case - but that's not very HTPC-like