No display/signal on monitor when evga gtx 670 is plugged in

[asusmobogtx]

No signal on my monitor when i plug it into my GTX 670

I spent all friday trying to set up my pc. My mobo has two pci-e slots , one is 3.0 x 16 the other one is 2.0 x 4 . My monitor shows : no signal when i plug it into the gpu {bios loads and OS loads , gpu fan functions too.

When i plug my monitor into mobo onboard graphics everything works properly.

Last night i tried another thing , i removed my gpu from pci-e 3.0 x 16 slot to the other slower slot which was pci-e 2.0 x 4 and everything worked like a charm. Graphic card works , signal is on and everything is running. The only problem is that this slot limits my cards power.

I need your wisdom guys ! Is there a faulty part in my build so i can just REM it or is there a solution to fix it somehow ?

My system :

Mobo ASUS P8B75-M LE, Socket-1155

CPU i5 2500k

RAM Crucial DDR3 BallistiX Sport 1600MHz 8GB kit(4GBx2)

PSU XFX ProSeries Core Edition 550W PSU

SSD Crucial v4 SSD 2.5" 128GB SATA 2.0

GPU EVGA GeForce GTX 670 2GB PhysX CUDA

 

[Robert17]

Did you disable on-board video chipset and enable discreet card in BIOS? Check your card's power cables?

 

[CaNsA]

In the BIOS, check you have specified which PCI slot to enable 1st for graphics.

HTH

 

[asusmobogtx]

Robert17
When in bios , i go to cpu - system agent configuration , video graphics , and there is an optiopn to select the default device :

Auto
iGPU
PCI-E
PCI
AGPU

by default it is set on auto
when i change to PCI-e and restart it switches back to Auto

CaNsA :

Where can i find these settings ? I didnt see them anywhere

 

[CaNsA]

You are looking in the right place mate, and yeah it should be set to PCI-E.
Are you deffo saving the changes when you make the change before you restart?

Does the bios date/time reset each time you restart the pc?

do you have another GFX card to try in that slot?

 

[asusmobogtx]

I click F10 , save changes and restart every single time.

Each time i restart the pc bios time and date stay intact.

I don't have another card unfortunately. But i plugged my gtx 670 into the slower pci-e 2.0 x 16 at 4x speed and i get a 8200-300 gpu score on 3dmark11 P. While the avarage score is 9-10k on the same setting.

My processor struggles even more , i get barely 5k on physics test of the same setting.
When normally people get 7-8k with processor like mine

here is my 3d mark score : http://www.3dmark.com/3dm11/5103833

here is the score of a guy with similar specs : http://www.3dmark.com/3dm11/4560812

difference is colossal. I had enough brain ****ing for this weekend and so i have decided to take drastic measures. Do you think if i buy a new mobo (that supports my cpu and gpu ) it will fix the poor performance issue ? Cause i think my mobo is the real problem here