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4 fans and only 2 motherboard headers.

Discussion in 'Overclocking & Cooling' started by Owen Goldsmith, Jan 22, 2019.

  1. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

    Hey,

    I have 4 fans in my PC but the motherboard only has 2 fan headers, one for the CPU fan and one for the case fan. I purchased a splitter and have connected the cpu fan, and 2 extra fans to the splitter.

    However, now all 3 fans run at full speed (quite loud) and the white LED's in the 2 fans aren't on.

    Any ideas why this is and what I can do to fix it?

    The mobo is MSI B450M PRO-M2 and the 2 LED fans are three pin.
     
  2. NMBlack

    Hitman

    Joined: Sep 21, 2013

    Posts: 532

    Location: London

    Looks like you might be trying to run voltage-regulated fans from pwm mobo headers, or you need to set a fan curve in bios?
     
  3. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

    so what would you suggest I do as an alternative? I have taken a look on speedfan and the fans arent recognised individually by the motherboard.
     
  4. Grandmaster Fap!

    Sgarrista

    Joined: Jan 10, 2004

    Posts: 9,179

    Location: T'Northwest

  5. LuckyBenski

    Mobster

    Joined: Dec 28, 2017

    Posts: 2,840

    Location: London

    As NMBlack says, you'll need to use DC voltage control for 3-pin fans. The Phanteks hub does a nice tidy job of converting PWM signal from motherboard headers into DC voltage variation. But it's possible your motherboard can do it already - try adjusting it in the deeper Speedfan settings.
     
  6. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

  7. Grandmaster Fap!

    Sgarrista

    Joined: Jan 10, 2004

    Posts: 9,179

    Location: T'Northwest

    It shows you can run it with a sata cable but i just run it with it plugged in to the CPU fan header(as thats usually always pwm) and it was never a problem, more than enough power and i ran six fans from it!
     
  8. doyll

    Soldato

    Joined: Jul 1, 2011

    Posts: 7,468

    If you want to be sure you won't damage your mohterboard fan header use the Sata power lead to PSU. While some fan headers can power more than 1 amp of total load many are rated 1 amp, and 4x fans rated 0.1 amp each will easily pull 0.3-0.5 amp and some up to 0.6-0.8 amp each when starting up .. so if they pull 0.3 each that is 1.2 amp total so header can handle it .. but if 4 fans are pulling 0.6 amp startup it is 2.4 amp load and that could easily damage fan header.
     
  9. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

    Yeah, I have free SATA power connectors on my PSU anyway so no need to skip them.

    I have bought and installed this however speedfan is not showing any fans except the GPU. Any ideas why this could be? The fans are powered and spinning but again not LED lit and running at 100%.
     
  10. doyll

    Soldato

    Joined: Jul 1, 2011

    Posts: 7,468

    You should have one fan on the Phanteks hub sending it's rpm signal to motherboard header it is plugged into. On my hub it's the white socket. Manual explains it all.
     
  11. LuckyBenski

    Mobster

    Joined: Dec 28, 2017

    Posts: 2,840

    Location: London

    You can switch settings on and off to display and/or edit fan speeds. Go through all of the config several times with a fine toothed comb... It's not always obvious what setting changes what
     
  12. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

    Still no luck. I have followed the manual. I have the 4 pin connector and the sata connector. Checked bios and ensured CPW header set to PWM. CPU fan is plugged into Fan 1 and the BIOS is showing the fan speed now for the CPU, but nothing showing on speedfan even when I go into configuration and advanced mode.
     
  13. Grandmaster Fap!

    Sgarrista

    Joined: Jan 10, 2004

    Posts: 9,179

    Location: T'Northwest

    For a test, just unplug the sata cable and run it from the cpu header. You may be unlucky and speedfan doesnt recognise the ITE chip on your mobo so cant see the fans, ive had this happen. You could download Argus monitor and see if that see's the fans.

    Also do you have a bios setting for your fans like silent/normal/manual etc?
     
  14. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

    I'll give that a go and let you know. The only settings showing in the bios is smartfan and then the options to set at what temps the fans increase speed.
     
  15. Owen Goldsmith

    Associate

    Joined: Jan 17, 2019

    Posts: 17

    Downloaded Argus monitor and the CPU fan shows up so looks to be an issue with Speedfan. No LED's still but not the end of the world, I will get some separate RGB strips instead. Cheers for your help guys!
     
  16. MaXxBoulton

    Hitman

    Joined: Jan 11, 2019

    Posts: 888

    Location: Dagobah system

  17. doyll

    Soldato

    Joined: Jul 1, 2011

    Posts: 7,468

    Akasa PWM splitter are the worst I've seen, and I used several different ones. They put too many leads into each of the power and plug connectors so if user moves wires around much they flex-stress/harden and break. So when you open up case to do something when it's closed up and started fan with broken wire doesn't run.

    These are much better:
    https://www.overclockers.co.uk/ek-water-blocks-ek-cable-splitter-4-fan-pwm-extended-wc-9cq-ek.html
     
  18. DoneADougalOnSofa

    Wise Guy

    Joined: Feb 3, 2012

    Posts: 1,591

    Location: Bath

    I hate those multi-way PWM splitters! Never got mine to work. I just use these now: https://www.overclockers.co.uk/akasa-pwm-fan-splitter-ak-cbfa04-15-cb-071-ak.html

    Two fans per motherboard header.
    Dive into the Fan section in the BIOS, flick mode to DC (not PWM. Check first your mobo allows DC control, of course. Most do.) and run the calibration program.

    That should sort you out. Speedfan is a bit hit and miss sometimes. Used to crash my old rig as soon as I clicked on it- the entire system just powered off!
     
  19. Grandmaster Fap!

    Sgarrista

    Joined: Jan 10, 2004

    Posts: 9,179

    Location: T'Northwest

    What fans are they? LED fans usually just 'work', you dont have RGB fans instead do you?
     
  20. MaXxBoulton

    Hitman

    Joined: Jan 11, 2019

    Posts: 888

    Location: Dagobah system

    the problem with the cables is a lot of motherboard even thought they say PWM control just use DC control.

    should the first question here not be what fins dose he have and what amp's will they pull from the header, then we should see what the header can supple.
    lets be clear a fan header as a single fan connection for a reason, they have a max power output and some fans will blow fan headers if you put more than one on it.