Suggestions to run lower rpm at idle

[SaladFingers]

I'm trying to get two of my fans run a little bit lower at idle. Let me break this down:

 

My motherboard is the MSI X99s Gaming 7 (Link). It has 5 fan headers:

• 2 x 4-pin CPU
• 3 x 4-pin System

On the CPU headers I have 2 fans on a radiator for the CPU. Out of the 3 system headers, I'm using two of them with 2 PWM fans.

 

Now, all 4 fans are identical. The CPU headers allow me to get them as low as 12.5%, while the system headers only allow a 50%  What I would like to do is lower the system fans to have them idle as low as the CPU fans. Things I've tried so far:

• "Hacking" MSI's software actually allows me to run them considerably lower. Though this is really not ideal because I have to re-configure this manually after each restart.
• Currently using Speedfan, which allows them to get down to 39-40% but anything lower than that will cause them to completely stop.

 

I thought a lot about it, and the only solution I can think is to use 2 Y-splitters for each CPU header, and run each pair from one header. But I'm really not sure if it would be ok to draw 24V from each of those headers. Any insight on this? I could also try externally powered splitters, but it would become too messy for my liking. Also doing that means I would effectively lose control over fans independently and also I won't be able to see rpm readings for each and every fan. Any ideas?

[Torn]

Have you tried setting the fan curves in the BOIS? My MSI board offers a wider range of options there.

[SaladFingers]

Just now, Torn said:

Have you tried setting the fan curves in the BOIS? My MSI board offers a wider range of options there.

Yes, the BIOS options are exactly the same with their Windows software. Won't go lower than 50%. And actually I tried the "hack" again and I realized that they still get down to 40% and no less. I think the system headers are probably just made differently than the CPU headers at this point.

[JPotze]

15 minutes ago, SaladFingers said:

But I'm really not sure if it would be ok to draw 24V from each of those headers

clearly you don't know how electronics work. you pair them in parallel so it is still 12 volt . won't change that. you only draw double the current. but that is oke. your fan header of the cpu can even hold as much as 4 fans. just watch for the current draw of each fan. if that i like 12 volt and 0.05 amp you can connect 20 in theory. but i seriously wouldn't recommend that.

[JPotze]

3 minutes ago, SaladFingers said:

Yes, the BIOS options are exactly the same with their Windows software. Won't go lower than 50%. And actually I tried the "hack" again and I realized that they still get down to 40% and no less. I think the system headers are probably just made differently than the CPU headers at this point.

you can use the y splitter to connect the fans of the rad to the cpu header and connect a low noise adapter to it. but if you use an LNA and set the speed to 15% most likely the fans will stop completely. keep that in mind. PWM fans are more then often not able to ramp down below 30%.

[Torn]

Then if you still want the upper range of speeds your only option is the splitters. They won't draw double voltage, they will draw double current. You can run up to 3 fans per header assuming you are happy with them running the same RPM.

[SaladFingers]

3 minutes ago, JPotze said:

clearly you don't know how electronics work. you pair them in parallel so it is still 12 volt . won't change that. you only draw double the current. but that is oke. your fan header of the cpu can even hold as much as 4 fans. just watch for the current draw of each fan. if that i like 12 volt and 0.05 amp you can connect 20 in theory. but i seriously wouldn't recommend that.

Well no, I'm not that knowledgeable electronics which is why I asked. I assumed it would require 24V mostly because that's what I read online. But what you're saying makes more sense, it's not like plugging several things on the wall suddenly draw more than 110/220V either so yeah  Could you recommend software to check the amps?

1 minute ago, JPotze said:

you can use the y splitter to connect the fans of the rad to the cpu header and connect a low noise adapter to it. but if you use an LNA and set the speed to 15% most likely the fans will stop completely. keep that in mind. PWM fans are more then often not able to ramp down below 30%.

If I connect to the CPU header I really don't need an LNA because being able to set them bellow 40% will make them silent enough for my needs. I don't even have a choice, these fans state explicitly that they won't work with LNA adapters anyway. The fans currently on the CPU headers usually idle at 20% which is perfect for what I want.

[JPotze]

3 minutes ago, Torn said:

Then if you still want the upper range of speeds your only option is the splitters. They won't draw double voltage, they will draw double current. You can run up to 3 fans per header assuming you are happy with them running the same RPM.

that is not entirely true. it's like this. the header can supply x amount of amps at 12 volts. so lets say it is 0.3 amps. you can calculate how many fans you can connect. my fan is 0.05 amp so i could connect 6 fans to it if it supplied 0.3 amps.

[SaladFingers]

1 minute ago, JPotze said:

that is not entirely true. it's like this. the header can supply x amount of amps at 12 volts. so lets say it is 0.3 amps. you can calculate how many fans you can connect. my fan is 0.05 amp so i could connect 6 fans to it if it supplied 0.3 amps.

So, without researching about what amount of amps my header can supply or my fans require, would it be safe to assume that 2 fans per header would pretty much be ok?

[JPotze]

Just now, SaladFingers said:

So, without researching about what amount of amps my header can supply or my fans require, would it be safe to assume that 2 fans per header would pretty much be ok?

that would be oke. if you can supply me with what fans you have maybe i can look it up for you. but i bet my money on it that you can run 2 fans with easy on 1 header.

[SaladFingers]

4 minutes ago, JPotze said:

that would be oke. if you can supply me with what fans you have maybe i can look it up for you. but i bet my money on it that you can run 2 fans with easy on 1 header.

Sure, it's the Noctua NF-A14 PWM 2000rpm

 

edit: From the site: "Max. Input Current 0,13 A"

[JPotze]

2 minutes ago, SaladFingers said:

Sure, it's the Noctua NF-A14 PWM 2000rpm

that is a 0,18 amp or 2,16 watt fan. i wouldn't put more then 2 on 1 header. 

[SaladFingers]

3 minutes ago, JPotze said:

that is a 0,18 amp or 2,16 watt fan. i wouldn't put more then 2 on 1 header. 

Yeah my bad, I was looking at the 1500rpm specs. So you think two would be ok for my specific motherboard then?

[JPotze]

 

2 minutes ago, SaladFingers said:

Yeah my bad, I was looking at the 1500rpm specs. So you think two would be ok for my specific motherboard then?

yeah that would be fine. rule of thumb is 1 amp with a margin of .2 amps. so 0.8 amps. yours are .18 so 3 or 4 should technically work. 

if you want a security on that you can always buy this.

http://www.newegg.ca/Product/Product.aspx?Item=N82E16812119248&cm_re=pwm-_-12-119-248-_-Product

 

this splits the voltage and rpm/pwm signal cables . so the psu supplies the voltage and the pwm regulates the speed.

[SaladFingers]

1 minute ago, JPotze said:

 

yeah that would be fine. rule of thumb is 1 amp with a margin of .2 amps. so 0.8 amps. yours are .18 so 3 or 4 should technically work. 

if you want a security on that you can always buy this.

http://www.newegg.ca/Product/Product.aspx?Item=N82E16812119248&cm_re=pwm-_-12-119-248-_-Product

 

this splits the voltage and rpm/pwm signal cables . so the psu supplies the voltage and the pwm regulates the speed.

Yeah I considered that option but I'm trying to keep it as clean looking as I can. Anyway, I got all the info I needed, thanks a lot!

[nster]

You could also get the Phanteks PWM hub and just put all 4 on the same header. A nice elegant solution