Can I adjust fan speed when its connected with molex?

[Juusuhako]

My H100i pump is getting too much volt from my new PSU, hence causing a high pitch buzzing. I want to lower the voltage on the pump that it gets from a 15-pin sata (the big ones...)

My idea is the following:
- Sata-to-molex
- Molex-to-3pin
- 3pin goes into fan controller

Will I be able to adjust the voltage like this, or am I prevented because of molex? I've always read that a molex will run at 12V no matter what.

 

[KING_OF_SAND]

My H100i pump is getting too much volt from my new PSU, hence causing a high pitch buzzing. I want to lower the voltage on the pump that it gets from a 15-pin sata (the big ones...)

My idea is the following:
- Sata-to-molex
- Molex-to-3pin
- 3pin goes into fan controller

Will I be able to adjust the voltage like this, or am I prevented because of molex? I've always read that a molex will run at 12V no matter what.

Your SATA power shouldn't be doing more than 12v. SATA only does 3.3v, 5v, and 12v. You may either have a bad H100i or a faulty PSU. You may want to find a way to check that SATA voltage because if it is pushing more than 12v (which is required for the h100i if I'm not mistaking) you have other problems. Such as damaging anything else that's being plugged into your SATA's.

 

[Juusuhako]

Your SATA power shouldn't be doing more than 12v. SATA only does 3.3v, 5v, and 12v. You may either have a bad H100i or a faulty PSU. You may want to find a way to check that SATA voltage because if it is pushing more than 12v (which is required for the h100i if I'm not mistaking) you have other problems. Such as damaging anything else that's being plugged into your SATA's.

Here's a quote from a forum post:

Another, that is my idea, is to use an adapter, dubbed the "voltage dropper" by the Corsair forum's community, to lower the voltage a little. This is equivalent to running the unit off of a fan controller set to about 90%.
How is it done? Plain and simple - a rectifying diode soldered in series with +12V line, encased as a male Molex to female Molex pass-through. Or as a 4-pin Molex to 3-pin fan header for H60. Just mind the diode's polarity!

The thing looks like this:

http://i39.tinypic.com/72vvns.jpg

Now, im not gonna fiddle with a diode, as the fan controller sounds like an easier solution. I dont believe theres anything wrong with the PSU. Its all new and all my components are running fine. The H100i did not have this issue with the old PSU however.

From what I can read it has something to do with the 12V rail putting out to much? :s

 

[jamesriley94]

I know some of the older H100s had issues with this.

The PSUs put out 12v plus/minus 5% - which is within ATX specification.

So, your PSU could be putting out 12.6v on the twelve volt rail. Now this doesn't necessarily damage any components so it isn't a fault, but it would make the pump spin up to 5% faster which can cause it to rattle/spin unevenly.

I haven't heard this happen with the new hydro series though, so I would double check to make sure that this is definitely the problem.

I had an H80 that did this, and I attached the 9v resistor that comes with the SP120 QE fans and it completely stopped any noise at all, and the temperatures weren't really affected at all - although it probably isn't recommended you do this.

If you got a molex extension, and then a molex to SATA converter, you could cut the 12v wire of the molex extension, and solder in a 12v resistor. This would limit the voltage to 12v even if the PSU was outputting 12.6v which would hopefully solve the problem. That's probably the best way to go about it, and soldering a little wire such as that wouldn't be difficult at all.

The issue with using a fan controller is that a lot of them work by constantly applying the maximum voltage, but rapidly turning the power on and off, rather than directly reducing the voltages. You don't really want the pump to be rapidly turned on and off in this manner as it could damage it, and if it's still receiving 12.6v to it, I'd guess there's still a small chance of the problem reoccurring.

 

[Juusuhako]

I know some of the older H100s had issues with this.

The PSUs put out 12v plus/minus 5% - which is within ATX specification.

So, your PSU could be putting out 12.6v on the twelve volt rail. Now this doesn't necessarily damage any components so it isn't a fault, but it would make the pump spin up to 5% faster which can cause it to rattle/spin unevenly.

I haven't heard this happen with the new hydro series though, so I would double check to make sure that this is definitely the problem.

I had an H80 that did this, and I attached the 9v resistor that comes with the SP120 QE fans and it completely stopped any noise at all, and the temperatures weren't really affected at all - although it probably isn't recommended you do this.

If you got a molex extension, and then a molex to SATA converter, you could cut the 12v wire of the molex extension, and solder in a 12v resistor. This would limit the voltage to 12v even if the PSU was outputting 12.6v which would hopefully solve the problem. That's probably the best way to go about it, and soldering a little wire such as that wouldn't be difficult at all.

The issue with using a fan controller is that a lot of them work by constantly applying the maximum voltage, but rapidly turning the power on and off, rather than directly reducing the voltages. You don't really want the pump to be rapidly turned on and off in this manner as it could damage it, and if it's still receiving 12.6v to it, I'd guess there's still a small chance of the problem reoccurring.

I bought the unit used (its from 2013, maybe a batch before they fixed it?). I dont see what else the issue can be, since it started after getting the new PSU and it is NOT the fans.

My fan controller is this NZXT, any way to tell if its one of those on/off ones or one running a set % all the time? Would I be able to adjust the volt with the method of cables I listed in the first post?

 

[jamesriley94]

I bought the unit used (its from 2013, maybe a batch before they fixed it?). I dont see what else the issue can be, since it started after getting the new PSU and it is NOT the fans.

My fan controller is this NZXT, any way to tell if its one of those on/off ones or one running a set % all the time? Would I be able to adjust the volt with the method of cables I listed in the first post?

As it gives 'minimum power to fans' as a percentage I'd assume it isn't voltage controlled - but I'm not really 100% sure. Usually the ones with sliders or dials actually are voltage controlled.

What PSU is it out of interest?

 

[Juusuhako]

As it gives 'minimum power to fans' as a percentage I'd assume it isn't voltage controlled - but I'm not really 100% sure. Usually the ones with sliders or dials actually are voltage controlled.

What PSU is it out of interest?

How else would it control the fans if it didnt adjust voltage? (since you said it might not be voltage controlled).

Its a Corsair RM850.

edit: oh right, it turns on/off, duuh. my bad, lol.

 

[jamesriley94]

As I said in the first post, most of them work by rapidly turning the fan on and off.

For example, if it provided power for 1ms, then turned it off for 1ms, then on the next etc... the fan would only run at 50% of it's normal speed.

I'd probably PM Grey_Beard if I were you to see if there's anything he can do to help. If it's a Corsair PSU then you'd hope it wouldn't cause you any problems with another Corsair product.

Double check with another PSU first to see if the problem still occurs.

 

[Juusuhako]

As I said in the first post, most of them work by rapidly turning the fan on and off.

For example, if it provided power for 1ms, then turned it off for 1ms, then on the next etc... the fan would only run at 50% of it's normal speed.

I'd probably PM Grey_Beard if I were you to see if there's anything he can do to help. If it's a Corsair PSU then you'd hope it wouldn't cause you any problems with another Corsair product.

Double check with another PSU first to see if the problem still occurs.

Yea, I just edited the previous post, to slow though, heh.

I did not have this issue with my old PSU. When I put in my new PSU in the old chassis I really, really dont remember having this issue either (I wouldve noticed); I first noticed when I put it in my new chassis. Obviously the chassis isnt causing it.

The only difference is the radiator being mounted on top, in the old it was bottom. I did however try and unmount it while it was on and placing it different ways but with no difference (hoping it was a bubble or something).

Surely Corsair didnt intend this to happen when they released any of their PSUs, after all it was out of their knowledge that this would happen with it running over 12V, and was only able to fix it after release of some of their PSUs.

I will try PM him. Thanks.