A Minor Problem to Solve: Doubling up on the CPU_FAN header

[BonzaiDuck]

Narcissism declines with age, but I'm truly pleased with my simple fan setup in my HAF midtower. Here's the summary.

1) I replaced the CM 200mm side-panel fan with the NZXT "190mm" 0.70A -- 166 CFM. Please -- don't tell me about the fan holes, or the possible noise imparted to the flimsy HAF sidepanel. I got that all covered. Sucker is QUIET at full-bore! For later reference, this fan is powered directly from the PSU.

2) Rear-exhaust is covered by a Panaflo/NMB-MAT 120x38mm FBA12G12H1BX -- 3-pin, 0.46A, 2,500rpm top-end -- connected to the CHA_FAN1 mobo-header. Complete thermal control off my ASUS P8Z68-v-pro mobo.

3) I replaced both of the "limp" Noctua fans on my NH-D14 cooler with a single Akasa Viper 140R -- a PWM fan connected to the CPU_FAN header. For later reference, the ASUS board provides a CPU_OPT_FAN PWM header in addition to the main CPU_FAN. I can't be sure if this option fan header is thermally controlled, just reviewing the BIOS and "Fan Expert" Win-software options. As posted several times to the point of exasperation -- my D14 now reduces my LinX load temperatures by another 5C.

The Viper is rated at 0.28A.

4) There is a problem with the CHA_FAN2 header on the ASUS board -- not detected until long after the Egg's return deadline, and never considered serious enough for RMA to ASUS. The header does, indeed, power fans. There is thermal control within BIOS like the CHA-FAN1, but I cannot tell if that's what's really happening: fan-speed monitoring either through ASUS AI Suite, HWMonitor or AIDA-64 shows erratic reporting of fan speed. It will alternate between 450 RPM and 220,000 RPM!!!

5) That leaves the PWR_FAN header -- not thermally controlled, but with accurate monitoring.

As far as I can tell, the motherboard will supply power up to 1.00A @ 12V to each of the headers. That would be equivalent to 60W total, or 12W per channel. I could not have misread the specs if I am so far powering 0.46A + 0.28A and the defective CHA_FAN2 or PWR_FAN port fully powers the 0.70A NZXT fan.

PROBLEM: I don't want to purchase an $80 Aquaero 5 LT controller just to thermally control one additional fan.

Here are some options -- probably in combination with each other -- which would alleviate the power draw on the motherboard and allow several fans at once to be controlled from a single PWM header. The second item may possibly allow for the 3-pin Panaflo and NZXT fans to be integrated into the PWM mix:

http://www.sidewindercomputers.com/sw8waypwmsps.html

http://www.svc.com/pwmx.html

This would add some "complexity" where I'd managed to achieve "simplicity." The main questions: Has anyone tried these items? And are they likely to work together without a problem? Are they reliable? Is there any risk to the motherboard?

The other possibility: If the CHA_FAN2 header simply supplies the requisite power to -- say -- the 0.70A fan, and it still varies the fan speed as a "percentage" based on CPU temperature, then I should be able to run the tach-wire and another 3-pin plug to the PWR_FAN port so I get control plus monitoring.

Any comments on this fan-header problem, in addition to thoughts about the other questions I posed?

Thank you!

The Duckster-Meister

 

[james1701]

http://www.newegg.com/Product/Produc...140114024935:s

I just ordered 3 of these. They draw power straight from power supply, but have a green speed wire to set speed from mobo. You can put 3 fans on each mobo header and not overload it.

 

[BonzaiDuck]

http://www.newegg.com/Product/Produc...140114024935:s

I just ordered 3 of these. They draw power straight from power supply, but have a green speed wire to set speed from mobo. You can put 3 fans on each mobo header and not overload it.

So . . . you'd think these items work the same way as the Swiftech device? I think they're about $6 cheaper. But they're both so cheap, I might get both to try out . . .

Who has more than two PWM headers on their mobo? I have to ask, because my Z68 is about two generations old or almost 3-years old. I get two PWMs, two controllable 3-pin jobs, and a 3-pin "PWR_FAN" plug on the mobo.

 

[james1701]

My Asus Z77 has all 4 pin headers. I am running 3 200mm fan, a 230mm fan, a 140mm, and 4 120mm fans. My H100i broke, and left 2 sets of 120mm fans non functional, and I am running 2 of the 200mm on a plain 3 pin splitter. The board can not get both up to 100% speed.

I think either will work. If you do get the Swifttec, let me know how it works. I think wiring would be cleaner. That is the first time I have seen that unit, and did not really find much for reviews on it.

I would also think you would want to limit each one to the same size and type of fan. You would not get constant performance from having a bunch of fans that run at different speeds.

 

[BonzaiDuck]

My Asus Z77 has all 4 pin headers. I am running 3 200mm fan, a 230mm fan, a 140mm, and 4 120mm fans. My H100i broke, and left 2 sets of 120mm fans non functional, and I am running 2 of the 200mm on a plain 3 pin splitter. The board can not get both up to 100% speed.

I think either will work. If you do get the Swifttec, let me know how it works. I think wiring would be cleaner. That is the first time I have seen that unit, and did not really find much for reviews on it.

I would also think you would want to limit each one to the same size and type of fan. You would not get constant performance from having a bunch of fans that run at different speeds.

The old [NVidia ESA-certified] Silverstone Commander had separate profiles for each of five 3-pin fan headers, and there were maybe four analog thermal sensor wires. You would only ever see the % with 100% of full power for each fan. The monitoring software was a separate program.

With the Swiftech splitter-board, each PWM signal wire responds to the signal for which only the first fan-port gets monitored, and they all get their share of amperage at the same 12V.

Since I've done it before, I'm pretty sure you could pull the yellow tach-wire from each fan with the crimped-on metal pin and barbs. Then find a spare or unwanted fan which has a three-pin plug to cut off. You'd just restore the wire with its pin to the plug leaving two holes vacant, and put it on the three-pin port.

Cannot you use the a three-pin, voltage-controlled cable on a four-pin plug? The PWM ports on my board are keyed to accept either type of fan.

If a port won't spin up a fan-configuration to full bore, then you'd think you may have exceeded either the individual capacity or total capacity of all fan headers. With some boards I'd seen, it was expressed as amperage-per-plug or total all plugs. My motherboard is limited to 1.0A per fan channel. One of the ports has a damaged or erratic rpm sensor. Another one cannot be thermally controlled unless you connect it to a PSU -- the PWR_FAN plug.

Add up the amperage on the two 200mm fans you say don't spin up all the way -- if they're connected to the same motherboard header with a splitter.

 

[james1701]

How did everything work?

I got my Evercool plugs in, but have not tried them. I have a new idea now. I ordered a 900D and plan to use a couple of large rads. I want to pick up a PWM fan controller, and use 3 fans on each channel. Since a controller like the Lamptron uses fan speed and not power to control them, it might be possible to do. Plus with the Evercool wires, the fans pull power from the power supply, and the controller. That should keep it working for a long time.

 

[BonzaiDuck]

How did everything work?

I got my Evercool plugs in, but have not tried them. I have a new idea now. I ordered a 900D and plan to use a couple of large rads. I want to pick up a PWM fan controller, and use 3 fans on each channel. Since a controller like the Lamptron uses fan speed and not power to control them, it might be possible to do. Plus with the Evercool wires, the fans pull power from the power supply, and the controller. That should keep it working for a long time.

I'm contemplating a big purchase later this spring for another computer build. Ordering the Swiftech 8W-PWM-SPL-ST "device" (Akasa, etc. simply provide a short cable harness) is chump-change, but I'm trying to find a PWM fan that will replace my NMB-MAT (Panaflo) 120x38mm 3-pin exhaust fan. The replacement would allow me to cable the large 200mm fan to CHA_FAN1 port.

So far, I've found a DELTA fan with max. CFM of 150. I need something a bit weaker, but still looking . . .

There's no doubt in my mind that anyone would have a problem with chaining some fans to the single PWM CPU_FAN port. It doesn't require using the same type or fan spec other than PWM to the Swiftech. But you can only monitor one of the fans attached, unless you run tach wires from the other fans to vacant mobo 3-pin fan ports.