Problem setting up GPU rig

[albyh]

Hi,

I'm trying to build my first mining rig and have got 4 x Sapphire VaporX R9 280x along with a Sapphire DualX 29 280x.

I can get the cards working on their own but the second I try 2 or more only the card plugged into a monitor seems to work with the others just returning SICK after 60 seconds.

I'm running Windows 7 x64 with an ASRock H81 Pro BTC with a Pentium G3420 and 8GB DDR3 RAM along with a 750 and 850W power supply.

If anyone could shed some light on this issue I'd be very grateful I've been at it for days now

Thanks

[miner765]

Have you resolved it? If yes, how? If not, then try putting dummy plugs into your GPU's with no monitor.

[albyh]

I've finally solved it after over 20 hours of messing 

The moral of my story has been don't skimp on the power supplies!!!

The 2 850W and 750W power supplies I bought costing £30 and £40 respectively together wouldn't run more than 1 card at a time.  I've now replaced them with 2 x Corsair Gold 850W Full modular power supplies and one of these runs 3 cards on its own no problem.

I don't know if it helped that these have enough PCI-E power connecters for all the GPU cards rather than trying to use the molex adapters that came with the cards.