Sign in with
Sign up | Sign in
Your question
Solved

Help With Multi-GPU Mining Setup

Tags:
  • Graphics
Last response: in Graphics & Displays
Share
January 22, 2014 8:32:43 AM

Hey guys, I just finished putting together a crypto currency mining rig and am having a bit of trouble. The machine will power up with all fans running and such, however there is no display being outputted onto the screen. Now usually this would not be a huge problem, however this is the biggest build I've done before and so I want to make sure that there's not an obvious mistake I've made before I pull half the thing apart to start checking things. So to start, the machine has four Radeon 7990 GPU's on a MSI 970A-G43 mobo running through two PCI-e x16 risers, and two PCI-e x1 risers. The system is powered by two 1000W PSU's and has 8 gb of ram and an AMD Sempron 145 processor with the factory heatsink. Like I said before the system will power on without any apparent failure however there is no output to the display. It appears there is no sound on the board to give beep codes, or either I am receiving no beep codes because there has been no noise. I am wondering which card will be the default video output as the board does not have built in graphics. Should I unplug all but one card to install the OS? Do the multiple PSU's need to be configured in a certain way? Should I grab a less powerful card and connect that to install OS? Any other issues I may have overlooked? I can list the exact part numbers below if needed. Thanks for your time!

EDIT:
Incase you ask I have been through the sticky on this forum of non-boot/post/power issues and checked all of those things. I will be checking RAM later today.

More about : multi gpu mining setup

January 22, 2014 8:44:14 AM

did you happen to link the two powersupplies together via the green and gray cable or are you using a power supply splitter cable that links the two 24 pin connectors together? i run one of these in my rig

man 4 7990s give me one please I wouldnt mind quad xfire haha.


i would install with one card, load the drivers then reboot and reload again
m
0
l
January 22, 2014 8:45:48 AM

How do you have the second power supply connected to your motherboard?

My guess would be this is the issue. The second power supply is not receiving a power-on signal and does not know to start sending power to the graphic cards it's connected to. Since the cards are receiving some power via the motherboard, but insufficient power to actually work. It's like turning on a system without connecting the auxiliary power connection.

-Wolf sends
m
0
l
Related resources
January 22, 2014 8:50:04 AM

since you are running two PSU's im guessing you have a 24 pin splitter to make sure they are both powering on at the same time. Your primary card should be in the PCI-e x16 slot 1, make sure you are powering it the PSU that is running the 24 pin and 4/8 pin that supplies the cpu and motherboard, this will ensure it is powering on when the motherboard does. sometimes just a split second in the power up can cause some issues with the videocards.
m
0
l
January 22, 2014 8:51:34 AM

Wolfshadw said:
How do you have the second power supply connected to your motherboard?

My guess would be this is the issue. The second power supply is not receiving a power-on signal and does not know to start sending power to the graphic cards it's connected to. Since the cards are receiving some power via the motherboard, but insufficient power to actually work. It's like turning on a system without connecting the auxiliary power connection.

-Wolf sends


true but if the main power supply is powering the ftwo cards or whatever there should be still video, I can turn my second power supply of then boot and it will work but not see my second card, dont try to turn the second one off when its on your computer will shut off haha
m
0
l
January 22, 2014 9:25:48 AM

So let me make sure I'm understanding correctly; Both PSU's have to be connected to the Mobo using a splitter? Currently one of the PSU's is NOT connected to the mobo so that sounds like that is the issue. Another quick question is the Motherboard is configured in such a way that the first PCI-e slot is one of the x1 slots, should I plug the main card into that one, or into PCI-e #2 which is an x16?

Splitter I found doing a quick Google:
http://www.amazon.com/Vantacor-Dual-Adapter-Cable-2-way...
Is this what I will need or should I obtain a "Add2PSU" adapter? Also, what needs to be done about the 8 pin connector on the motherboard? Should there be a splitter for that also or is it correct to only have one PSU connected to the 8 pin?

Thanks for the quick response guys!
m
0
l
January 22, 2014 9:37:59 AM

the splitter from amazon is all you need. Your primary power supply hook up to the computer like you normally would if you were only using one PSU. take the splitter and plug it into the motherboard and primary PSU, it will look like an extension cable for the psu. the other plug with only two wires will plug into the 24pin of the second PSU and that will turn that psu on when you press the power button on the case. I would use the primary PSU to power the primary videocard and harddrive. Then use the secondary PSU to power any other Videocards, fans, and harddrives.

You will not need to use any of the 4/8 pin plugs off the second PSU for the motherboard. the only things need to be plugged in are the 2 wire splitter to the 24pin, and any 6/8 pin pci-x for videocards, molex for fans, and sata cables for harddrives and opticals.
m
0
l
January 22, 2014 9:44:41 AM

If you want to test for now grab some wire and split it in two hook one wire from the second powersupplys green wire to the first powersupply then do the same using the gray wire now they will turn on and off together
m
0
l
January 22, 2014 9:53:38 AM

Ok I may try that quick fix later today. But I will order the splitter and put that in in a few days and see if it works, then I will mark this thread as solved. One more quick question, Opinions on how many GPU's each PSU should power. I currently have it setup with each PSU powering two of them, but what are your opinions on setting this up?
m
0
l

Best solution

January 22, 2014 9:58:30 AM

Newegg recommends a 1000 watt PSU for a Crossfire set up, so I'd recommend two cards per PSU.

-Wolf sends
Share
January 22, 2014 10:40:38 AM

That was my exact reasoning behind putting two on each PSU. The manufacturer's website recommends the same. Thanks Wolf!
m
0
l
!