Latest posts of: xxx2003gs

Hello, I see your results.

1. The card is a PCIE switch using the PEX8614 chip, which costs about $ 40.
2. And can only work in PCIE 2.0 4X to 8 PCIE 2.0 1X modes. Because the PEX8614 can only support up to 12 PCIE LANEs and 12 PCIE Ports (1 INPUT and 8 OUTPUT). And your design forgets to use GPIO to configure troubleshooting. So you can not work in PCIE 16X mode.
3. More than six new GPUs in a system (old GPU, such as 7870 it can work 12 because it only needs half the resources), you need to configure the BIOS MMIO, usually its BIOS option is Above 4G Decoding The
4. Most motherboards can support more than eight GPUs, but you need non-standard BIOS. Such as Panda's custom motherboards using the X79 BIOS, add Haswell CPU microcode support to get the Above 4G Decoding option.
5. The AMD driver does not support more than eight GPUs in an OS. If you want to make a 16 / 32GPU system. You must use Intel VT-D and SR-IOV technology, and through virtualization to achieve. Or you customize an AMD driver (but it is very difficult).
6. So on the lightning miners can make more than 8GPU system, I think this is not possible, because you do not understand how to achieve. You just made a PCIE switch card, it's very simple.

Sorry for my english. Hope you can understand.

Quote from: kilo17 on April 29, 2017, 05:01:20 AM

Quote from: OhGodAGirl on April 28, 2017, 10:33:14 AM

Interesting.

Well, for a start, both AMD and NVIDIA don't support 32 GPUs with their drivers. You'd need a custom driver - and I doubt you're going to give that technology to the masses, for free. What kind of mode are you running in? You'd need to use virtualization technology for anything above 8 GPU for AMD, 16 for NVIDIA - I might be wrong on the NVIDIA though ( they may only support 8 ).

kilo17, I would expect you to have known this.

EDIT: Changed about to above.

I appreciate the confidence you have in my knowledge (makes me feel good). I must disagree with you on this one, although I could be wrong. The real limits are the mobo BIOS and not the drivers per se. jstefanop is probably better to answer this question than I am since he has been in direct contact with Greg Stoner from AMD but here is a quote from Greg

"It does not matter if you have the all the cards on single CPU with 16 GPU’s ( You will need multilevel PLX switches) or two CPU with 8 GPU’s. On 2P system the critical issue is the system bios need have enough PCIe resources for Doorbell BAR, IO BAR, MMIO BAR and Expansion ROM. One thing beyond 16 GPU’s you heading into new world for both AMD and NVIDIA."

I have posted a link to this thread from jstefanop and Greg Stoner previously and if anyone is interested I will post it again, it is about running greater than 8 gpu's per rig. It is a great read.

Since I am not familiar with the custom motherboards that Panda or Lightening are using and I have not peaked at the BIOS from them either I cannot say how it is set up.

On a side note, I have been in discussions to have a 12 and/or 16 GPU mobo manufactured and there has not been any issues per the engineers at the manufacturer as long as the mobo doesn't have unnecessary crap on it.

cheers Wink