Fan Count for Commander Pro

I am planning a new build. I plan to use 13 fans(Corsair LL120 RGB). I am trying to figure out if I can run all my fans through Commander Pro. In the specs is says each fan header can handle up to 1v with a total of 4.5 for all headers. The two LED channels say they can handle 4.5 volts each.

The LL120s dray .3V per and (I think) .62V for the RGB.

Does that mean I can run up to three fans per PWM channel? 13 fans would not go over the 4.5 total. It would be the same for the LED channels, I would be under 4.5V per channel. I want to use the icue software for curve management and the lighting. I would be using two led fan hubs with one connection being a spliter, 7 on one channel and 6 on the other. I also have 2 in loop temp sensors that are not Corsair, can those be connected to the temp sensor inputs on the Commander Pro?

 

I plan to run the LEDs from the water blocks and the pump to the onboard headers and control them with the motherboard software. I plan to run the flow of the water pump through the CPU fan header.

 

I am looking for any advice or a better way of doing it, if there is a better way. I would appreciate any help.

We've seen issues, in the real world, with 3 fans on a single PWM channel when using 3-way splitters, even though it was under the 1A limit for a single header. We typically suggest sticking to 2 way splitters. That said, I have heard from folks that have used 3-way splitters successfully.

 

For the number of fans that you are talking about, we usually suggest using a powered PWM hub.

 

The LED channels and LED power don't count at all in this, by the way. They are on separate rails.

Thank you. I just watched your video on making Corsair extension cables. Brilliant! Thank you for that. Would I not be able to use icue to control RPM and Lighting if I use a powered PWM Hub? Would icue pick up my fans if I use a powered hub and connect to the motherboar? Would icue pick up my fanlighting if I use the node pro and connect to the motherboard? I have 3 360 rads in this loop and I will need the fans but I want to use icue to control them.

Also, could I use 2 commander pros? If I did that, could I get away without using a power pwm? Just go straight into the ComPro? I would only have to double up one of the channels.

Yes, you could certainly do that!

Thank you! The best thing I learned today was that I can use CAT5 to make RGB extension cables. Off topic but that blew me away. Thanks again.

always worth the read :)

 

RGB Faq with diagrams

 

http://forum.corsair.com/v3/showthread.php?t=173880

The way to really understand why three LL120 fans are unlikely to work is specs.

First thing to remember that to be in spec, a variance of up to 10% is considered normal and within spec tolerance. That means if you are told a max amp draw is 1, it will be between .9-1.1 as a rule. Check you RPM on fans, I have 10 and even though they could be all set to 1000rpm none will have the exact same RPM, as an example of this behavior, or "tolerance".

 

So the LL120 is a .3a draw, so 3 will be a 9a total draw, so within spec it should be doable right? Probably not, if you reduce the 1a limit on the CP and add 10% to the fans...you see the numbers do not match. Also this does not even count the possible difference caused by the splitter.

 

I run 3 fans a channel on my CP, but they are little over .2a, so total of around .7 to 7.5 with a CP of as low as .9. The numbers line up and it works great.

 

its about the numbers not the number.

It isn't just about exceeding the current tolerate for a specific header. You may find that the controls simply don't respond right on 3 way splitters. You may also encounter issues trying to set the fans to 0 rpm. I often find myself in a fan/splitter matching game, trying to find a working combination. I have hundreds of both and it is still annoying. It's better to make a plan around this, rather than get caught later.