So, I’m making a gpu mining rig and i’m trying to get away with just using an old Motherboard of mine Image
However, i can use the PCIe x1 port fine, the GPU is recognized and can mine but when i plug the second into the PCIe X16 it doesn’t boot (not even to the bios).
Should i buy a new MOBO, if so which one?
Your motherboard may be switching the primary GPU to the PCI 16 slot. Try connecting a hdmi or whatever other port that GPU might have to your monitor. Usually this is the case. Then you can access your BIOS and change back to onboard GPU as default if you wish.
ok, thank you. this is an improvement. now i get a error page saying “thread stuck in device driver”
What GPUs are you using and what Operating System?
I experience the same issue on my RX480 rig mining with Claymore’s miner. Usually it takes couple of Windows restarts to get it working.
I would recommend installing CCcleaner and cleaning your Windows Dump Caches.
I believe Zcash mining creates alot of temporary files which clogs the OS
I havent even been able to mine yet! I’m on windows 10
Does Win10 restart displaying this error or you see it at the miner’s terminal window?
when i boot with both in now i get a few start up lines of code then just a dark blue screen.
no windows
The issue could lies within few things - drivers,risers, psu and few more.
What kind of Graphic Cards are you using?
I’m using 2 Sapphire 8gb 480s .
My PSU is 750w
does it work with only 1 card in the pci-e 16x?
Nope , it’s strange.
Well the x16 port is made for graphiccards. If its not working with one GPU plugged in it directly then probably there is something wrong with your MB.
Try reseting the bios before you dump your MB.
I assume trying to reinstall windows doesnt work eighter.
looks like a VGA connector on that MB. Try to disable integrated graphics before everything else.
I haven’t tried order re installing windows , I thought about the intergrated graphics but I can’t seem to find it in the bios 
restart the computer and press delete. Some MB producers started to use different F buttons also… try them aswell
Ok , I just deleted the drivers and rebooted , plugged in the 2nd card and it shows me some likes of code (normal boot up) but then windows never loads .
I instead the drivers while using 1 of the cards , then when I reeboot with both it says “thread stuck in device driver”
