7V Fan speed limiter

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I'm gonna connect my 2 front intake fans to PSU because I don't have any more room on the motherboard. Is it ok to use 7V fan speed limiter?

Thanks for all the answers.
 
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you are right... I googled for the manual and there's nothing :).

2 front intakes on a Y splitter = yes, it's ok
top exhaust connected to CPU_OPT = yes, it should follow CPU_FAN speed.
Finding splitters = I know... had the same problem i my country too... good thing I found that Amazon ships computer parts down here :).

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While searching I stumbled upon this:
http://www.tomshardware.com/answers/id-1967178/water-cooler-powered-pin-header.html

It looks like it is expected to have full throttle on the pump 3-pin connector... this is the same to connecting it directly to PSU on a molex. I think you are safe doing this... you wouldn't need the splitter right?... and hopefully you already have the molex adapter for fans :D

hwc1954

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Sure, a 7V adapter would work to slow the fans down. Just be sure to use one adapter on each fan. No splitter after the adapter.

Just for reference, it's fine to connect multiple fans to a single MB fan header using splitters or hubs. You just need to check the rating of each fan and make sure the total is less than the rating for your MB's fan headers. They are probably good for 1.5 to 2 amps (18 to 24 watts), but to be on the safe side, staying under 1 amp (12 watts) should be fine. Check your fans, but the Nocturas I have are rated in the 1 to 1.5 watt range. Running multiples is no problem.
 

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Thanks for all the answers. I have Corsair 750D case. The fans I want to connect to 7V adapters are stock front intake (2 fans). So there should be no problem with that? No damage to any component?

Wasn't really thinking about splitters. What would you recommend. Would you pick the splitters? I don't have any spare header on the motherboard. Also I was thinking about fan controllers. Any recommendations?

And again thanks for answers.

 

hwc1954

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The disadvantage of hooking the fans to a power supply molex is that they will run at a constant speed. You can can slow this down with the 7V adapter, but then the fans can't crank up under heavy load. If you run them without the adapter, then they are at full scream, even when unnecessary.

The advantage of hooking them up to fan headers is that you can probably (depending on the MB) have them automatically vary speed depending on the CPU temp. Slower when temps are cool. Faster when things heat up.

The specifics would depend on your fans and motherboard, but with any normal fans, it should certainly be fine to run three fans from the headers on the MB. Some Corsairs are 0.1 amp. Some are 0.3 amp.
 

atmos929

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do those fans have led lighting? Does the the case have a switch to turn on and off those leds (fan still on)??.

I am asking this because corsair uses custom pinout on their fans, for the above scenario, their 3pin connector is not standard. (and chances are they do not even have a 3pin connector but a molex adapter)

If their connector is standard and it fits the MoBo jack, I think you are ok. I just wanted to make sure. I've seen ppl asking how to connect such fans on the MoBo, but these fans are designed to be directly connected to a molex.
 

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Thanks for all the answers. What if I use splitter. Will both fans connected to one fan header work the same. Any problems? Also I use Asus Maximus VII Hero MB and Corsair H75 CPU Cooler. I have both fans of H75 connected to one fan header with splitter because Corsair says that both should be connected to one and the pump should be connected to ANY NOT CPU fan header. Should I Connect one CPU fan to other CPU Fan header (in this motherboard OPT_CPU fan header).

 

hwc1954

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It should be fine to connect both CPU fans to the same CPU fan header with a splitter. I'm assuming that the splitter supplied with the Corsair is properly wired, so that only one of the two fans reports it's speed back to the header. Both fans will turn at exactly the same speed.

I don't know anything about water cooling, but I understand you want the pump to be constantly on full (i.e. not slowing down with temp). So make sure the fan header you have it connected to is always on full, not variable speed. If not, you could always connect it to a Molex power supply connector.
 

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What if I connect one case fan (top exhaust) to one spare CPU fan header (I have both CPU fans connected with splitter to one CPU fan header on motherboard). Will it respond to CPU temp or will it mirror the fans that are on CPU fan header or something like that. Is that bad?
 

atmos929

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considering that is a jack for an second CPU cooler fan, my guess is that it doesn't its own speed control, but it may use the same speed control signal generated by and for CPU_FAN (the first one)

So... if you connect top exhaust there, chances are it will run alongside the CPU fans.
 

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Thanks for the answer.

What about connecting pump directly to PSU. Is that good? I would get an extra motherboard case fan header since I have pump connected to case fan header as it was instructed by Corsair.
 

atmos929

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Then I am guessing it would work at full speed. I don't have experience with water cooling, so I am guessing here that the pump also changes its force depending on cooling demand, so if you connect it directly to PSU, it would be full speed all the time (or almost half if you put the 7V limiter)...

Now... chances are it has a constant speed and it is expecting 12V all the time. I'm shooting blind here... you ought to check in the water cooler manual whether it has info on the requirement for that pump voltage line.
 

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Thanks for the answers. I'm pretty sure there is no manual for Corsair H75. I was already looking for it and I couldn't find it (turned everything around).

I will probably use splitter for my front 2 intake fans (any problems?,if I understand correctly they will only run both with the same speed? right?) and connect my top exhaust fan to CPU header (it will respond to CPU temp? right?). The problem is I can't find any Y splitter in my country. Yeah, I'm not joking you can't find it.
 

atmos929

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you are right... I googled for the manual and there's nothing :).

2 front intakes on a Y splitter = yes, it's ok
top exhaust connected to CPU_OPT = yes, it should follow CPU_FAN speed.
Finding splitters = I know... had the same problem i my country too... good thing I found that Amazon ships computer parts down here :).

==============
While searching I stumbled upon this:
http://www.tomshardware.com/answers/id-1967178/water-cooler-powered-pin-header.html

It looks like it is expected to have full throttle on the pump 3-pin connector... this is the same to connecting it directly to PSU on a molex. I think you are safe doing this... you wouldn't need the splitter right?... and hopefully you already have the molex adapter for fans :D
 
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