Can anyone tell me if this programme allows that the fans are completely off until a certain temperature is reached?

I'm building a passive (but powerful, i7 4770S) system, but would like the ability for the fans to come on during, say, video rendering or playing games.

Thanks

You could do this with Speedfan by setting the target temp to be very high. However, any software solution is not fully failsafe. What if the software crashes? I therefore wouldn't depend upon it.

I wouldn't be too fussed about stopping the fans entirely and running passive. PWM control on many modern motherboards is good enough that it will slow fans down to some very low speeds when cooling is not required. Good fans running at 500rpm might be no louder than the electrical component noise in a typical system anyway.

I have a PWM-DC controller that allows me to set slow speed voltage and effectively can be used to stop a fan, even if a motherboards own PWM control won't allow it to run at any lower speed.

build it first.
then see what the slowest speed the (SPCR recommended) fan(s) can run to keep sytem from throttling during gaming/rendering.
then see if you can actually her them.
then worry about fan control.

When compatible with the motherboard of choice, Speedfan on its own let you set the fan speed at 0%, but stopping the fans mostly depends on the mobo headers capability and the fans itself.

Thanks guys, this is very helpful

Looks like PWM wont work very well on my board as I only have 3 headers and have 4 fans.

So I am now thinking I'd like a hardware fan controller. Lamptron look good but they need loads of power as they are aimed at the gamer market. Can anyone recommend a controller?

What board, which fans?

I have the Asrock Z97 Extreme 6 and using Phanteks XP PWM 140mm fans.

What I would like to do, depending on what I am doing is:

1. Have fans off
2. Have fans run at 600rpm; and
3. Have fans on full

What is the easiest way to achieve this?

To confirm, I have 4 case fans in my system only. My PSU and my CPU are both passive.

Probably a fan controller might help with such a stepped behaviour, but if I were you, first of all I would find out whether the fan can be actually stopped: personally I don't know the ASRock control utility, in case you might also try to configure SpeedFan, as I didn't understand whether you were able to do so or not.

Anyway, in my experience almost always there's no need to stop a case fan, when driven enough low it will be actually inaudible.

Even if you could, under motherboard control, keep the fans turned off under idle or low system stress conditions the adaptive nature of the Haswell processor would cause issues without active CPU cooling. For example Asus have at least one motherboard where a temperature can be set in the BIOS for the chassis fans to turn on, for example 50C. So it could be run with all fans off in your scenario. But once a passively cooled Haswell processor is loaded the rise in CPU temp happens too quickly for the chipset to react and prevent thermal throttling. Worse still the motherboard reacts to that by setting all fans to 100% speed and only begins to lower them once the processor cools down.

I don't know if you have tried the QSA adapter that came with your fans. It is supposed to reduce the fan rpm range to something like 300 to 900 and would allow a much quieter idle. However the reduced airflow would probably not fit in with the absence of a CPU fan. What you could consider if the QSA adapter works is to use a CPU fan such as the Noctua NF-F12 120mm which runs from around 300 rpm if your CPU cooler takes this size of fan. Or for full size 140mm the Noctua NF-A14 which again runs from 300 rpm. This would give the benefit of active CPU cooling with minimal noise levels at the lowest BIOS settings.

Hi Lodestar, thanks very much for your thoughts and time. I am struggling to understand what you have written.

My CPU is passively cooled and I'd like it to stay that way. Temp never goes above 50 with my big Nofan on it.

So I am talking only about the 4 case fans

I see, so active CPU cooling is not an option. So in that case have you tried the QSA adapter that came with your fans? Does it reduce idle speeds and does it do this without pushing up CPU temperatures too much?

Not yet, these Phanteks are still out of stock everywhere, I cannot find them!

So all your questions are just hypothetical ones?

Well, its all pre-ordered, just waiting for it to arrive!! Had to do some research before deciding pwn fans are what I want...

Out of stock from my local supplier as well. If you have not got them yet I would suggest you consider the Noctua NF-A14 PWM as a replacement. Does not need an adapter for lower speeds as its speed range starts from 300 rpm. Will cost a bit more but worth it.

Whether the OP can replace those Phanteks, there should be no need of PWM fans, with that motherboard.
Something cheap and good sounding like the Prolimatech Vortex (either Blue or Red), or the Antec TrueQuiet should work well.

what do you mean no need for pwm?

As far as I know the relevant headers works when you pair them with voltage controlled fans, and whether the mobo is on the way, you should be able to actually check that soon, I mean, before ordering any case fan.

Yes, modern motherboards do allow control of 3-pin fans as well as 4-pin PWM fans. However the issue is how much control. For example PWM fans usually can be controlled for the whole of their speed range. With 3-pin fans it will depend on the board. Typically it is the equivalent of 6V or 7V to 12V. With say a 1200 rpm 3-pin fan this would mean minimum idle speeds of around 700 rpm. To get a quiet idle a lower speed 3-pin fan like the Antec TrueQuiet 140mm could be used but the lack of top speed is probably going to be crucial given the passive Haswell setup being proposed here. (As tested by SPCR this was only 700 rpm). With a PWM fan like the Noctua NF-A14 you get both the low speeds and the high speeds in one fan. The motherboard BIOS controls of most boards now including probably this Asrock tend to have a Silent mode. This will hold the speed of a PWM fan down to the minimum until the CPU hits a temperature of around 40C. So at idle you get not only low fan speeds but also speeds that do not vary much due to factors such as ambient temperature.

but isn't the point of speedfan that I set the parameters, irrespective of temp?

If you don't want to have any temp dependend rpm, you won't need speedfan at all. Set fans to 5V or 7V and close the case. Why bother with any software at all?

And if you want to change fan voltages on the fly, think about using some fanmates or other fan controller hardware.

Because as I write above, I want to be able to do three things:

1. Turn them off
2. Run at 600rpm
3. Run at full

Depending on what I am doing. The system will be ok with no fans, but just want to turn them on when playing a game or editing photos or video.

That's the point, it depends on the board: whether it's on the way, the OP have just to test that soon (all he needs is a case fan, and I think he should have at least the stock ones).
At first glance, it might not need PWM fans.

If I'm not wrong, probably lodestar is thinking mainly about a pure BIOS control, without any program to manage the fans (SpeedFan or ASRock).
From this viewpoint, his remarks are more clearly understandable: but with reference to the max speed issues, mostly it depends on the specific enclosure.

This is theoretically possible using software. Possibly SpeedFan but certainly CPUID HWMonitor PRO. Fans have a duty cycle 0 to 100% equivalent to 0 to 12V. So by using software a fan could be set to % duty cycle and it should turn off. However it most cases it won't turn off. With PWM fans this is because they are typically set to run at a minimum speed for something like the 0 to 30% duty cycle range. So setting a fan like this to 0% duty cycle will not stop it. The other issue is whether the motherboard will allow a fan to be stopped. Most will restart a stopped fan because it is assumed to be a fault. Only a hardware fan controller which breaks the 12V line to cut off power can guarantee to turn off a fan.Not a problem. Could be done in the BIOS or could be done using the supplementary fan control software from Asrock or if the boards supports it, SpeedFan.Again, no problem at all. Same solution as with running at a fixed speed.

But this is a really cumbersome way to run a PC. That's why I recommend fitting a PWM fan like the Noctua NF-A14. It would idle in your system at around 350 rpm and would be verging on silent. The system would automatically respond to increased CPU temperatures caused by gaming and this would not necessarily mean running the fans at full. It would also cope with varying ambient temperatures, basically a fit and forget arrangement.

And you're saying that the benefit of the Noctua is that it can run as slow as 350rpm vs the 600 in the Phantek? That is a good point if I am understanding you correctly.

Can you control at what point it goes down to 350?

Yes, Asrock provide their own fan control software as a free download and you can use it for that purpose. It's part of the ASRock A-Tuning utility and is called FAN-Tastic.

Got you. So in the absence of being able to switch the fan off, your advice is to get a fan with a really low RPM capability. Looking at the data on this site, though, I would expect the Phantek at 600 and the Noctua at 350 to be similar in audidlbe performance, with the former moving more air?

I have not seen any data for the Noctua at 350 rpm but I would expect it to be significantly quieter than if it was running at 600 rpm. Or the Phanteks PH-F140XP running at 600 rpm. A 140mm still moves a reasonable amount of air at 350 rpm but if it was not enough you could set it via software to run at 400 or 450 rpm or any other speed. So at least the option is there to do this.