New Mining Rig setup help needed

[Ghost__]

Hello everyone,

I am pretty new to this forum and to mining in general. I just liked the idea a lot so i bought my first rig.

My setup is:

M/B: GIGABYTE 990FXA-UD3 REV 4.0
Processor: AMD FX 6300
RAM: 8 GB
GPU: 6 Sapphire R9 280X Tri-x OC
OS: Windows 8

The problem that i have is that i have 6 usb 3.0 PCI Risers 1x to 16x. When i put the card in the riser the motherboard doesn't recognize it at all..! Right now i have only one card attached on the motherboard and is working perfectly.

Can you please tell me if anyone has the same mobo which riser cables to use in order for the cards to work properly with this mobo...?

I've thought to use 16x to 16x unpowered ribbons but i don't know if this is correct.

Any help will be appreciated..!

Thanks

[Starscream]

Are you using powered risers? If so you gotta power the molex, if not, well, than you got the wrong risers.

Also, you're late to the party with GPUs

[Ghost__]

Yes i am using risers like this http://www.ebay.co.uk/itm/UK-PCI-E-1x-to-16x-Powered-USB-3-0-Extender-Riser-Adapter-Card-Bitcoin-Litecoin-/310897618647?pt=UK_Computing_CablesConnectors_RL&hash=item4862f12ed7

[Starscream]

Yes i am using risers like this http://www.ebay.co.uk/itm/UK-PCI-E-1x-to-16x-Powered-USB-3-0-Extender-Riser-Adapter-Card-Bitcoin-Litecoin-/310897618647?pt=UK_Computing_CablesConnectors_RL&hash=item4862f12ed7

And you connected the molex?

[Ghost__]

Yeap..! Otherwise the GPU doesn't power up..!