second GPU not dedected should i cross fire

[hostmaster]

I have one radeon 270 X and just bought radeon r9 290 but it2s not dedected what could be the reason?

[ineedit]

I have one radeon 270 X and just bought radeon r9 290 but it2s not dedected what could be the reason?

Loads of possible reasons but cross is not the answer

What does cgminer -n return?

[Gator-hex]

No crossfire required for mining. Only gaming.

Could be low power. If your graphics card has multiple rails you might have overloaded a rail.

[ineedit]

No crossfire required for mining. Only gaming.

Could be low power. If your graphics card has multiple rails you might have overloaded a rail.

Gator-hex means PSU rather than graphics card but it could well be the problem.

[Gator-hex]

No crossfire required for mining. Only gaming.

Could be low power. If your graphics card has multiple rails you might have overloaded a rail.

Gator-hex means PSU rather than graphics card but it could well be the problem.

oops. lol yeah. I meant "If PSU has multiple rails"  

Try spreading the load over as many cables as possible.

[Hueristic]

try a dummy plug.

[PeerMedia]

Try removing the 270 and putting the 290 in its place, is it detected then? If so, then its either the riser or the PCIe slot.