Results 1 to 18 of 18
  1. #1
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia

    2 4 pin pwm fans on a splitter to motherboard?

    I can't find any conclusive evidence of whether it would work or not if I put 2 4 pin pwm fans on a 4 pin pwm y splitter cable in plugged them both into the cpu fan header on my motherboard. I know it can hurt the motherboard if you over draw so how do I know? I've been through the manual and checked the specs online as well but can't find anything certain. It's a gigabyte ex58-ud3r motherboard and I want to have 2 scythe kama 1600rpm fans on pwm together on my megahalems. here's the fan. it draws 1.32w at peak. thoughts?
    http://www.newegg.com/Product/Produc...-161-_-Product
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  2. #2
    Senior Member


    Bobnova's Avatar
    Join Date
    May 2009
    Author Profile Benching Profile Folding Profile Heatware Profile Rosetta Profile
    That should be fine.
    I don't know of any mobo headers rated for less then an amp, and one amp at 12v is 12w.
    You'll need to make sure only one fan is feeding tach information to the mobo if you want the tach reading to be anywhere near accurate.
    "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe." -- Einstein (maybe)

    Thinking about an Asus motherboard? Think again.

    How to check your PSU with a multimeter.

    17bXw5t51rEBXGavJFMJsC8g7HQgThUGc7

  3. #3
    Member
    Water Cooling Sticky Reading Enforcement Official
    m0r7if3r's Avatar
    Join Date
    Jun 2010
    Location
    Marietta, GA
    Author Profile Heatware Profile
    You should be fine, if you wanted to be super-fine you could split the PWM wire (4th pin) from the mobo, run an rpm wire from 1 fan to the mobo, then power the fans direct from the PSU and this would allow the mobo to effectively control the fans while not having to worry about power draw (also is, imo, the RIGHT way to do this)
    If years were seasons, this December would be the December of our December.
    -Abed #sixseasonsandamovie

    Heat

  4. #4
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    Quote Originally Posted by Bobnova View Post
    That should be fine.
    I don't know of any mobo headers rated for less then an amp, and one amp at 12v is 12w.
    You'll need to make sure only one fan is feeding tach information to the mobo if you want the tach reading to be anywhere near accurate.
    I like to think the people that make the y splitters would take this into account but maybe that's wishful thinking. i'll look into it
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  5. #5
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    Quote Originally Posted by m0r7if3r View Post
    You should be fine, if you wanted to be super-fine you could split the PWM wire (4th pin) from the mobo, run an rpm wire from 1 fan to the mobo, then power the fans direct from the PSU and this would allow the mobo to effectively control the fans while not having to worry about power draw (also is, imo, the RIGHT way to do this)
    I'll try that if plugging straight in to the mobo seems too risky or shows signs of problems. Sounds like the only concern is proper rpm readings (i hope). Thanks for the help gentlemen I think I'll try it.
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  6. #6
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    If you look close at the pictures of this y splitter only one of the plugs has a 4th pin (pwm?) Looks like it might work!
    http://www.newegg.com/Product/Produc...82E16812718001
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  7. #7
    Senior Member


    Bobnova's Avatar
    Join Date
    May 2009
    Author Profile Benching Profile Folding Profile Heatware Profile Rosetta Profile
    Yup, that splitter does what you want it to with the tach pin. It should work great.
    "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe." -- Einstein (maybe)

    Thinking about an Asus motherboard? Think again.

    How to check your PSU with a multimeter.

    17bXw5t51rEBXGavJFMJsC8g7HQgThUGc7

  8. #8
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    Much appreciated
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  9. #9
    Registered Nasty Nige's Avatar
    Join Date
    Mar 2011
    Location
    Leicestershire UK
    Hi im ruunnign a similar set up with a couple of sythes in push-pull on a megahalems. whats the effect if I was to just "cut" one of the rpm cables so its effectivly a 3 pin set up & only "1" fan is being read off the 4th pin
    Beer will get you through times of no money better than money will get you through times of no Beer.

    ASUS P6X58D-E
    I7 950 @ 3.2GHz & Cuplex Kryos Pro W/Block
    12gb DDR3 @ 1600mhz
    OCZ 120GB SSD
    XSPC Dual Bay Res - Twin loops 12W DDC-T
    Rads EX240 (Internal) & PA120.4 (external)
    WD caviar Green 1tb *2
    WD 300gb *2
    2 Nvidia GTX560 Ti OC SLI - on Air
    NZXT Phantom

  10. #10
    Member
    Water Cooling Sticky Reading Enforcement Official
    m0r7if3r's Avatar
    Join Date
    Jun 2010
    Location
    Marietta, GA
    Author Profile Heatware Profile
    Quote Originally Posted by Nasty Nige View Post
    Hi im ruunnign a similar set up with a couple of sythes in push-pull on a megahalems. whats the effect if I was to just "cut" one of the rpm cables so its effectivly a 3 pin set up & only "1" fan is being read off the 4th pin
    uh...rpm is the 3rd pin, pwm is the 4th pin. You can cut a tach wire, but if you cut the PWM wire it will just run full speed all the time.
    If years were seasons, this December would be the December of our December.
    -Abed #sixseasonsandamovie

    Heat

  11. #11
    Member
    Join Date
    Mar 2011
    Location
    New England
    Before you cut any wires, try pulling the pin out of the connector. There should be a set of small holes along one side of the connector, one for each pin, that you can insert a small paperclip into in order to release the pin from the connector housing. Then you can simply fold it out of the way and tape it down. This will allow you to keep the wire intact for future use, if you should ever want to use the rpm sense again.

    Ethan
    GA-X58A-UD3R --- i7-950 @ 4.025GHz 1.33V w/HT --- Prolimatech Megahalems w/ 2x Scythe SY1225SL12H-P
    6GB G.Skill 9-9-9-24 1400 --- Galaxy 560GTX Ti @ 990MHz --- 2x Intel 40GB SSD RAID-0 & Various HDD
    Antec Three Hundred --- 3x Scythe SY1225SL12H
    --- Home Brew Fan Controller --- Antec Earthwatts 650

  12. #12
    WhitehawkEQ's Avatar
    Join Date
    Dec 2010
    Location
    Planet Norath
    Before you go cutting anything, PWM spliter power cables are made so that 4 wires goto 1 fan and 3 wires go to the other fan, the MB reads RPM info from only 1 of the 2 fans connected but has the PWM wire going to both fans.
    If the power spliter cable is 3 wire only, it won't work on PWM fans.
    A+ Certified, Going for Network Engineer
    Folding User Stats

  13. #13
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    it worked out great. motherboard didn't start smoking or anything and the fans are spinning over 100rpm slower during prime95 small fft's than with one fan. also one less place i have to run a big @$$ molex from the power supply and it's nice and quiet until it has reason not to be.
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  14. #14
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    Ok not sure what to make of this. HWmonitor randomly shows the cpu fan at 0 rpm off and on but i have the side of the case off and the fans are clearly spinning. huh?

    edit; idk it doesn't happen in bios so nvm. i guess hwmonitor is crap. it also says my 12v rail is at 2v LOL
    Last edited by Brando; 04-24-11 at 04:04 PM.
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  15. #15
    Member
    Water Cooling Sticky Reading Enforcement Official
    m0r7if3r's Avatar
    Join Date
    Jun 2010
    Location
    Marietta, GA
    Author Profile Heatware Profile
    HW monitor is fine, I bet you have both RPM wires running interfering signals.
    If years were seasons, this December would be the December of our December.
    -Abed #sixseasonsandamovie

    Heat

  16. #16
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    There's only one rpm wire. One of the fan plugs has 3 pins instead of 4. It's this one.

    http://www.newegg.com/Product/Produc...0e9796a37726f9

    I watched fan speed in bios for 15 min waiting for fluctuations and nothing. Only hwmonitor does it. Also, 12v rail shows 10v low yet my pc works great.
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  17. #17
    Member
    Water Cooling Sticky Reading Enforcement Official
    m0r7if3r's Avatar
    Join Date
    Jun 2010
    Location
    Marietta, GA
    Author Profile Heatware Profile
    Quote Originally Posted by Brando View Post
    There's only one rpm wire. One of the fan plugs has 3 pins instead of 4. It's this one.

    http://www.newegg.com/Product/Produc...0e9796a37726f9

    I watched fan speed in bios for 15 min waiting for fluctuations and nothing. Only hwmonitor does it. Also, 12v rail shows 10v low yet my pc works great.
    HWMonitor is reading directly from bios. My 12v rail reads wrong too, but it reads wrong across multiple programs (HWMonitor and Everest both read it ~2.3v). You can't always trust your sensors. You should try changing around which fan has its rpm read
    If years were seasons, this December would be the December of our December.
    -Abed #sixseasonsandamovie

    Heat

  18. #18
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    Quote Originally Posted by m0r7if3r View Post
    HWMonitor is reading directly from bios. My 12v rail reads wrong too, but it reads wrong across multiple programs (HWMonitor and Everest both read it ~2.3v). You can't always trust your sensors. You should try changing around which fan has its rpm read
    will do

    edit:so far so good. straightened the pins as much as possible, switched fans, and plugged\unplugged a few times. no false readings yet. maybe too much anti oxidation coating or whatever they call it if any. reminds me of the time i bought a mag lite and it wouldn't turn on even after switching batteries. then i rubbed the spring against the battery contact plate for a minute and it miraculously started transferring electricity between the 2 surfaces. idk.
    Last edited by Brando; 04-26-11 at 11:05 PM.
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •