where can i plug 2 noctua fans with gigabyte ud4p mobo?

garazh · Post by **garazh** » Wed Apr 15, 2009 12:46 pm

i got a problem. i've just built an i7 system (in my signature). i'm using noctua NH-U12P SE1366 as a CPU cooler. it has 2 fans. however i was able to install only 1, because the motherboard gigabyte ud4p has only one CPU FAN connector. what do i do? can i plug second fan to one of connectors, that named SYS FAN or the like?

thank you.

shleepy · Post by **shleepy** » Wed Apr 15, 2009 1:02 pm

The only purpose of labeling the fan connectors is for monitoring purposes. Feel free to plug the second one into "sysfan" or the like - just remember where you plugged in which fans when you're monitoring fan speed in BIOS and your OS.

ntavlas · Post by **ntavlas** » Wed Apr 15, 2009 1:25 pm

You could also use a y splitter, this would allow you to run both fans at the same speed and free the rest of the headers for other uses. Normally I am a little weary of running two fans off a single header but the noctuas draw so little current (0.09 amps) that this shouldn`t be a problem.

garazh · Post by **garazh** » Thu Apr 16, 2009 6:12 am

ntavlas wrote:You could also use a y splitter, this would allow you to run both fans at the same speed and free the rest of the headers for other uses. Normally I am a little weary of running two fans off a single header but the noctuas draw so little current (0.09 amps) that this shouldn`t be a problem.

yeah.. i almost forgot, that CPU fans will probably feel better, if they are controlled equally and simultaneously. strangely, there was no splitter in the cooler box.

second. do i understand right, that a motherboard checks a CPU temperature, and appropriately changes its fan speed? will it do so, if i plug the second fan to, say, SYS FAN1?

one more question. what to do with the case fans (p182 has 3 of them)? i connect them just to the power supply. i can change their speed by switches on the back - "high-mid-low". is it possible to make them changing speed automatically - depending on the system loading?

will it be better, if i use some kind of fan controller?

sorry for these silly questions. this is my first time creating such a serious system.

InfyMcGirk · Post by **InfyMcGirk** » Thu Apr 16, 2009 6:56 am

They're not silly questions.

Personally I don't like the manual fan controllers with knobs on the outside of the case. My current system uses Zalman Fanmate2s, so my fans are permanently dialled down to slow/quiet. But then in my current system I use a big external watercooling radiator for CPU/GPU, so I only need a couple of slow case fans to keep everything else cool. There's no temperature control.

You can use something like Speedfan software to control the speed of fans on various fan connectors on your motherboard, but not all headers are controllable on all motherboards: your mileage may vary. Also, Speedfan is like any other software in that it can crash or misbehave in subtle ways which means it's not best suited to protecting components from over-heating or other critical jobs.

Probably the best solution I've seen is the mCubed Big-NG fan controller. It can control up to four fans (or more using splitters, which it supports) using its on-board microcontroller and a set of temperature probes included in the kit. You initially set it up using software, but once it's programmed, it works on its own even when no OS is loaded, so it's immune to any software failures. You can define curves to the fan speeds are ramped up according to temperature automatically. It can also turn off the fans altogether below a certain threshold.

I plan to use a BigNG in my next system (which will be aircooled).

However, if you don't mind twiddling knobs occasionally then a conventional case-mounted fan controller will be cheaper and arguably less fiddly to set up, requiring fewer cables.

ntavlas · Post by **ntavlas** » Thu Apr 16, 2009 10:41 am

Some sys/aux fan headers can automatically control fan speed based on ambient temperature. My gigabyte 780g for instance dials the exhaust down to 600 rpm. You could try comparing two of the stock fans, one running off the sys header and the other connected to a molex, then experiment with different settings high/med/low...

garazh · Post by **garazh** » Thu Apr 16, 2009 5:22 pm

i'm screwed up. i've bought a noctua cpu cooler for lga1366 socket (a newest, i guessed, in the whole world of cpu coolers), and this cooler has 2 120mm super-duper silent fans, and they both have 3-pin connectors! how can they be regulated by a motherboard at all!?

my bad. i'm gonna return this to newegg, and buy something else. what do you think about Scythe MUGEN-2 SCMG-2000 120mm Sleeve CPU Cooler. it's cheaper, but i think it'll do its job better?

ntavlas · Post by **ntavlas** » Fri Apr 17, 2009 12:41 am

Well, if you`ve already opened the package (don`t know what the return policy is) you could plug in the fans and see what happens. Some motherboards can control 3 pin fans on the cpu. The sys and aux fan headers are 3 pin anyway, so in the worst case you got a couple of excellent case fans.

InfyMcGirk · Post by **InfyMcGirk** » Fri Apr 17, 2009 12:50 am

I believe most/some 4pin headers in the motherboard can accept 3pin connectors (the little latch bit is offset from centre to match 3pin plugs). Then in the bios, choose 'legacy' or 'voltage' or similar (not 'auto' or 'pwm'). Sorry but I can't remember the exact setting. Perhaps the mobo manual might be more helpful here?

garazh · Post by **garazh** » Fri Apr 17, 2009 5:59 am

thnx, guys.

yep, i've already unpacked the cpu cooler and installed it. and the thing is - the motherboard is not able to control the cpu fan, though, it's showing its speed.

first thought was to return the cooler to newegg. second thought - why do they produce such cpu coolers - with 3-pin connectors? perhaps, somebody needs them? how are they used then?

what about fan controllers? for example, Scythe KM01-BK "KAZE MASTER". it has 4 temperature sensors and is able to control up to 4 fans. is it good idea to use it?

garazh · Post by **garazh** » Fri Apr 17, 2009 6:26 am

well.. RTFM forever!

here's what i've read from the noctua site's FAQ:

Can I run Noctua fans on 4-pin PWM connectors and use my mainboardâ€™s automatic fan controller?
Yes. You can simply connect our fan's 3-pin connector to the 4-pin PWM sockets of today's mainboards so that the fourth pin that transmits the PWM signal is left blank (due to the shape of the connector, there's no danger of reversing polarity). Most current mainboards are capable of controlling fans not only via PWM, but also by adjusting the supplied voltage. In some cases, this may require you to change BIOS options like "Fan Control Mode" from "PWM" to "Voltage" or "Analog". Please consult your mainboar's manual in this regard. However, most current mainboards use an "auto" setting by default that automatically chooses PWM or voltage based regulation according to the connected fan.

it looks like i should switch my mobo's "Fan Control Mode" to something else - like "Voltage" or "Analog". i'll try this in the evening.

garazh · Post by **garazh** » Fri Apr 17, 2009 7:14 am

the motherboard's manual confirms this:

CPU Smart FAN Mode
Specifies how to control CPU fan speed. This item is configurable only if CPU Smart FAN Control is set to Enabled.
Auto Lets BIOS autodetect the type of CPU fan installed and sets the optimal CPU fan control mode. (Default)
Voltage Sets Voltage mode for a 3-pin CPU fan.
PWM Sets PWM mode for a 4-pin CPU fan.

well, tonight i got something to do

.

garazh · Post by **garazh** » Mon Apr 20, 2009 7:50 am

i've bought a Y-splitter for the noctua cooler fans, plugged them both to CPU_FAN connector (through the ultra-silent adapters - to set both the fans at 900 rpm maximum) and switched BIOS parameter "CPU Smart Fan Mode" to "Voltage". besides, i've replaced the case fans. i've installed:

Scythe SY1225SL12M 120mm "Slipstream" Case Fan 1200 RPM, 68.54 CFM, 24.00 dBA - on back;
Scythe S-FLEX SFF21D 120mm Case Fan 800 RPM, 33.5 CFM, 8.7 dBA - on top;
Scythe GentleTyphoon D1225C12B3AP-13 120mm Case Fan 1150 RPM, 63 mÂ³/h, 16 dBA - in the lower compartment between PSU and HDDs.

then i've tested my system: i7-920 2.66GHz @ 3.2GHz (CPU-Z shows 3.36GHz), HT turned off. the rest is in my sig.

after 1 hour of prime95 (all 4 cores loaded at 100%) CPU temperature was 54-55C, system - 40-41C. easytune6 showed the CPU fans at 886-915 rpm. in the same time i was able to browse the internet, and could HARDLY hear my computer! actually, i started to hear rather how velociraptor seeks, than how the fans blow.

however the picture was changed, when i turned HT on. even on the middle settings (CPU fans are up to 1100 rpm - i've replaced the adaptors) prime95 (8 cores at 100%) easily heated the CPU to 61C in 15 minutes. after that i've stopped testing. it looks like i need to remove the adaptors at all to let the CPU fans spin at 1300 rpm. i just wonder, if it helps..

garazh · Post by **garazh** » Mon Apr 20, 2009 6:57 pm

well. i've removed those adaptors from the CPU fans connectors and repeated a test. in 1 hour of prime95 working (i7-920 @3.36GHz with HT - all 8 cores @100% loading) the CPU temperature was about 58-59C. the system temperature didn't exceed 40C. i was able to hear the CPU cooler's fans, when prime95 running. however, i think a smart tweaking of the CPU cooler's fans can help me. for now - in the practicaly idle state - i almost don't hear my computer.