Better fans, worse results.

[earwicker7]

I wasn't really happy with the results I was getting with my watercooling setup (they weren't bad, but they weren't what I expected), so I did a little research, and it turns out the fans I was using on my radiator were very low power (less than 40 cfm), so I replaced them with some that have almost 120 cfm. I have two external triple radiators, one for the CPU/chipset, and one for the GPUs. In order to do a little side-by-side testing, I left the old fans on the GPU loop; the first thing I did was put my hand over the fans on each radiator... the new ones seemed to put out less air. Eh, I'm just imagining things, I thought. Then I did a batch of LinX, and the temps are actually worse.

I'm wondering if the problem is that my fan controller is overloaded. I have six fans on my radiators, and only five channels on my fan controller, so what I'm doing is daisy-chaining them into two channels, one for each radiator. This seemed to work pretty well with the old fans; the controller showed a consistent 1000 RPM for each channel, which is right around where the fans are rated (I think the manufacturer said 1100 max). With the new ones on the CPU loop, each channel, both old and new fans, are showing inconsistent numbers which dip up and down, maxing out at 1000 RPM. Here's the strange thing; the new fans are rated at max 4250 RPM. So it appears that the new ones are only operating at 1/4 capacity.

Any ideas? Again, my gut instinct is that the new fans are drawing too much power for just a single channel, but I have no way of dedicating a single channel to each fan.

 

[earwicker7]

Just did a little experimenting; I changed to 3 channels with two fans on each. One channel had one old fan and one new fan... the new fan on this channel kicked up substantially; the controller is still reading 1000 RPM, probably because of the old fan being on the channel, but the new fan is most definitely going faster than that, and churning out some serious air. The channel with two new fans is still behaving poorly.

Any ideas on how I can solve this? The channel with two new fans is still really slow.

 

[earwicker7]

This is strange... they all fired up at full power. Then about a minute in, one of the channels dipped back to 1000 RPM.

 

[Slaymate]

What fans did you buy?

 

[earwicker7]

Gentle Typhoon D1225C Series, 4250 rpm. I called the people who sold the fan and the controller to me; they're thinking there may be too many amps for the controller to handle, so they're going to contact NZXT. It makes sense... the reason it is dropping down after running for a minute is that there is no headroom left in the capacitors. If that's the case, I'll have to get a new controller.

EDIT--Got my response:

"Broke out some quick math.

Watt total = Volts * Amp draw

Max Watt per channel = 10W

12V x 0.56 amps per fan = 6.72 W per fan so two fans brings you in at 13+Watts per channel.

It is throttling down for sure."

So anyone know of a six-channel controller?

 

[aspire]

Sunbeamtech Rheosmart 6 Fan Controller Products Model: PL-RS-6 [PL-RS-6] : Performance-PCs.com, ... sleeve it and they will come

This should do the trick, 6 channels and 30W per channel.

 

[earwicker7]

Cool. Right now I'm just running them all at full power off of the PSU... very loud, but very chilled.