Double PSU + 6x GPU - Fan not spinning under load

CoreolCoreol Member Posts: 30
edited September 2016 in Mining
I recently setup a new rig with the following specs:
4x XFX RX480 GTR Black on an ASROCK mobo powered by two Corsair RM750x (750w Gold rated).

I've paperclipped one of the RM750x's so that it starts up without being connected to the motherboard - currently it supplies power to the HDD and 1 card.
After almost 24 hours of testing the system is running stable so far, dual mining Eth and LBRY.
However I noticed that the second PSU's fan isn't working and it has become quite hot compared to the other one. There the fan is spinning normally.
Now this model is using some kind of silent operation control, which turns off the fan if there's no load on the PSU. I'm afraid that if there a sync issue, it might damage something, especially since I plan to add 2 more cards in this rig.

Has anyone else had a similar problem?

I've know ordered a "multiple power supply adapter", maybe that will solve the problem. I'll post an update once it arrives.

Comments

  • Dr_House86Dr_House86 Member Posts: 566 ✭✭✭
    The Adapter will solve that shit ;)
  • CoreolCoreol Member Posts: 30
    That's what I am hoping for! Thanks for the input :)
  • TruthchanterTruthchanter Member Posts: 549 ✭✭✭
    what is the multiple psu adapter name?
  • CoreolCoreol Member Posts: 30
    Just got the adapter. It's turning the PSU on but it's still not spinning the fan of the second PSU. Basically I just wasted 20$..
  • Zorg33Zorg33 Member Posts: 220 ✭✭
    edited September 2016
    exactly, that adapter can be replaced with an $1 12V relay and some wiring.
    and it has nothing to do with the psu's fan. It should be controlled by the internal thermal sensor of the PSU. -> PSU is most probably faulty.
    Try to swap the two and see if it's spinning or not.
  • CoreolCoreol Member Posts: 30
    Zorg33 said:

    exactly, that adapter can be replaced with an $1 12V relay and some wiring.
    and it has nothing to do with the psu's fan. It should be controlled by the internal thermal sensor of the PSU. -> PSU is most probably faulty.
    Try to swap the two and see if it's spinning or not.

    Hi and thanks for the input. I just replaced it with a new unit I had stocked - Still the same result. Running the rig at room temperature the temp goes up while the fan on the 2nd unit still isn't spinning. Guess it needs to be connected directly to the MB for whatever reason...

    Just a warning to others - don't use "Corsair RM750x" in a dual PSU setup. You get the power but your 2nd PSU will probably melt at some point :)
  • hasherhasher Member Posts: 642 ✭✭✭
    @Coreol My entire farm uses Corsair RM and AX series PSUs. One of the best and most reliable PSU's available in my opinion. I also use add2psu adapters on all my rigs. I don't have any issues with the PSUs or the adapters. Just because you turn the PSU on, doesn't mean the fan has to spin. It will only spin under heavy load. You're obviously not pulling enough power from your PSU to have it need to turn the fans on. There was sticker that was attached to your PSU which tells you about the "silent operation" mode - did you not bother to read it?
  • CoreolCoreol Member Posts: 30
    edited September 2016
    hasher said:

    @Coreol My entire farm uses Corsair RM and AX series PSUs. One of the best and most reliable PSU's available in my opinion. I also use add2psu adapters on all my rigs. I don't have any issues with the PSUs or the adapters. Just because you turn the PSU on, doesn't mean the fan has to spin. It will only spin under heavy load. You're obviously not pulling enough power from your PSU to have it need to turn the fans on. There was sticker that was attached to your PSU which tells you about the "silent operation" mode - did you not bother to read it?

    Dear hasher,

    I appreciate your input and yes - I tend to do my research before posting anywhere or for that matter - buying something. Actually I've done more research for this PSU than I cared to do in the first place.
    Most of the "solutions" I've seen on the web were talking about the same "not enough load" or "silent operations mode", which is bull* when you draw over 1k from the wall and one PSU fan spins and the other PSU fan doesn't while it gets hot to the point where you can barely touch it...

    But rejoice - today I've installed Win10 instead of Win7 and the second fan started spinning miraculously at the same time as the first one when under load.

    I don't know exactly what the issue was, but at least this is solved for me.
    Also, I stand corrected and in the end the Corsair PSU as well as the Add2PSU were not a complete waste of money for my setup.

  • Zorg33Zorg33 Member Posts: 220 ✭✭
    edited September 2016
    @Coreol BTW keep in mind that regular ATX PSUs don't like if you only draw 12V from them, you have to plug a dummy load in 5V/3.3V too.
    Also this may have something to do with your fan not spinning.

    Plug in an 5 ohm 5W resistor and see if the fan starts spinning.
    Or plug in a 12V light bulb into the 5V on the ATX24 connector, that's perfect for testing and it can be plugged in diagonally in pci-e conenctors too for 12V test. :)
  • CoreolCoreol Member Posts: 30
    @Zorg33 Thanks for the info! Very useful. I'll also give that a try.
    Currently the fans are spinning perfectly after switching to Win 10. Still a bit of a mystery to me...
  • wntrb0ywntrb0y Member Posts: 28
    edited September 2016
    I know some Corsair PSU's come with that "Zero-RPM fan technology" where its apparently "so efficient" that the fan wont spin until the PSU is under significant load. Is that a possibility here?


    --edit: reading>me.... Looks like you already looked into this.
  • stefantstefant Member Posts: 1
    Hi I need some help. I have a mining rig with 2 PSU (800W) and when I try to switch the second PSU on the whole system crashes when launching Claymore miner. Everything powered by the second PSU stops along with the PSU itself. I have tried swapping the PSU's, the riser cables, the GPU's, every possible combination but I have the same result. Does anyone have any ideas what can I do?
    The rig consists of an asrock H81 pro btc, 2 identical psu, 5 gpu rx570, 1 add2psu.
    Thanks in advance. -
  • lablettlablett Member Posts: 333 ✭✭
    stefant said:

    Hi I need some help. I have a mining rig with 2 PSU (800W) and when I try to switch the second PSU on the whole system crashes when launching Claymore miner. Everything powered by the second PSU stops along with the PSU itself. I have tried swapping the PSU's, the riser cables, the GPU's, every possible combination but I have the same result. Does anyone have any ideas what can I do?
    The rig consists of an asrock H81 pro btc, 2 identical psu, 5 gpu rx570, 1 add2psu.
    Thanks in advance. -

    The second PSU should always be on. By turning on the primary PSU your secondary PSU will start. Just make sure you primary PSU is powering your motherboard and hard disk. Also make sure a GPU is powered, riser & power, by the same PSU.
  • rmhrmh Member Posts: 410 ✭✭✭
    stefant said:

    Hi I need some help. I have a mining rig with 2 PSU (800W) and when I try to switch the second PSU on the whole system crashes when launching Claymore miner. Everything powered by the second PSU stops along with the PSU itself. I have tried swapping the PSU's, the riser cables, the GPU's, every possible combination but I have the same result. Does anyone have any ideas what can I do?
    The rig consists of an asrock H81 pro btc, 2 identical psu, 5 gpu rx570, 1 add2psu.
    Thanks in advance. -

    If you have an add2psu, why do you "try to switch the second PSU on"? It's must be on, if the primary psu is on, this is the only reason of add2psu.
  • QRSeamanQRSeaman Member Posts: 14
    Coreol said:

    Zorg33 said:

    exactly, that adapter can be replaced with an $1 12V relay and some wiring.
    and it has nothing to do with the psu's fan. It should be controlled by the internal thermal sensor of the PSU. -> PSU is most probably faulty.
    Try to swap the two and see if it's spinning or not.

    Hi and thanks for the input. I just replaced it with a new unit I had stocked - Still the same result. Running the rig at room temperature the temp goes up while the fan on the 2nd unit still isn't spinning. Guess it needs to be connected directly to the MB for whatever reason...

    Just a warning to others - don't use "Corsair RM750x" in a dual PSU setup. You get the power but your 2nd PSU will probably melt at some point :)
    some PSU's have a mode where the fan doesn't spin 100% of the time.
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