Any experience on PCI expansion cards?

KlintistwoodKlintistwood Member Posts: 140
Hello all,

I have a Asrock motherboard with 12 pci slots but not all of them deliver the same performance. Maybe I should send back the motherboard but that would mean stop mining for a while so I thought I could maybe maximize the potential of those working well by using a PCI expansion card.

There is a cheap one here: Aliexpress
Or a more expensive one here: Amazon (but with more than 500 reviews!)

I don't know what would mean in terms of bandwidth for the PCI slot ? Or power ? Or what would be the consequence for the OS ? (I'm using Ubuntu)

Anyone with experience on this?

Thanks
Laurent

Comments

  • mjmeansmjmeans Member Posts: 58
    Any motherboard that implements extra PCIe slots by using a built in expander can experience a performance issue with respect to those GPU's sharing the same CPU PCIe line. I haven't looked into your boards specs, but I know that the Biostar 12 GPU board specifically states in it's technical information that all 12 slots are direct to the CPU and don't go through any expander.

    I suspect that whenever you add an expansion card like this you could see a performance drop because you are dividing the bandwidth unless: 1) the expansion card's connection to the MOBO is a x4 or x16 one; and, 2) the expansion card separates the lanes rather than sharing lane 1.
  • KlintistwoodKlintistwood Member Posts: 140
    @mjmeans Thanks! I checked the specifications here: Asrock but couldn't find any indication except that all PCI 2.0 slots are x1 slots. I suppose it would not be a good idea to use an expansion card on those ones?

    I always forget it but I also have a 13th slot in PCI 3.0, would it mean that this one could take an expansion card without too much trouble?
  • mjmeansmjmeans Member Posts: 58
    It's possible. It depends on how that slot is wired to the PCI lanes on the CPU. But you would certainly want to go into BIOS and change the slot compatibility to 2.0. If the mobo has a BIOS settings for "mining mode" you will want to set that too. The Biostar mobo has a special mode for mining that improves the PCIe capability by sending special UEFI commands to the booting OS. If your mobo has that feature, then it's worth a try. But if it has that feature and you didn't install the OS with that feature turned on, you may end up having to reinstall the OS. When I was testing a Biostar mobo, I had to reinstall after changing that setting because the OS was unstable after the change. Good luck.
  • wirelessnet2wirelessnet2 Member Posts: 368 ✭✭✭
    umm. the amazon link is for a USB 3 PCIe expansion card. You cannot plug GPUs into that one. Do not try to, it will fry your card
  • KlintistwoodKlintistwood Member Posts: 140
    @mjmeans I'll check the bios, good idea. I hope it will not force me to reinstall, thanks!
    @wirelessnet2 Yes you can :) all my other PCI risers are PCI to USB3 to PCI, it's just that you need a PCI output to plug the GPU afterwards.
  • wirelessnet2wirelessnet2 Member Posts: 368 ✭✭✭
    @Klintistwood you cannot use the one you posted on amazon.com. If you want to argue, it's not my cards that are on the line. I don't think you understand that "USB 3.0" can be either the physical cable standard or the data transfer standard. Ask anyone else here and you will be proven wrong.
    Link OP posted: http://amzn.to/2yFfgfy
  • rmhrmh Member Posts: 235 ✭✭

    @mjmeans I'll check the bios, good idea. I hope it will not force me to reinstall, thanks!
    @wirelessnet2 Yes you can :) all my other PCI risers are PCI to USB3 to PCI, it's just that you need a PCI output to plug the GPU afterwards.

    @wirelessnet2 has right, this is not for PCI-E cards. http://amzn.to/2yFfgfy (lol)

    You need something like this:
    https://www.aliexpress.com/item/PCIe-1-to-3-PCI-express-1X-slots-Riser-Card-Mini-ITX-to-external-3/32787157605.html
  • KlintistwoodKlintistwood Member Posts: 140
    @wirelessnet2 yes, you're right, I'm sorry, I posted the wrong link. What I meant is that I'm using risers with USB3 cables in between but in the end it remains a PCI to PCI adapter.

    sorry for the confusion!
  • jsanzspjsanzsp Member Posts: 184 ✭✭
    the pci lanes is the problem biostar is working in these


  • KlintistwoodKlintistwood Member Posts: 140
    @jsanzsp wow that's almost tech porn :) Have you make this work with more than 10 GPU?
  • jsanzspjsanzsp Member Posts: 184 ✭✭

    @jsanzsp wow that's almost tech porn :) Have you make this work with more than 10 GPU?

    there are two problems, the pci lanes that the chipset is able to manage, and the drivers,that do not allow more than 8 gpu in windows on amd or nvidia

    Biostar seems to be working, there are for sale solutions like this but only compatible for their motherboards


  • mjmeansmjmeans Member Posts: 58
    jsanzsp said:

    the pci lanes is the problem biostar is working in these


    13 port expansion per PCIe slot? Is this real or a clever photoshop?
  • jsanzspjsanzsp Member Posts: 184 ✭✭
    mjmeans said:

    jsanzsp said:

    the pci lanes is the problem biostar is working in these


    13 port expansion per PCIe slot? Is this real or a clever photoshop?
    its the future of gpu mining
Sign In or Register to comment.