Crosshair V 7970 crossfire trouble

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Hi every one,

im new on the forom so my name is Nicolas, im 24 and i live in Monaco.

My config is :

Mobo : Crosshair V
CPU : FX 8150
Ram : Ripjaw 1600 mhz 16 Gb
GPU : 2x ATI 7970 3Gb
HDD : 2x Seagate 1 Tb
2x Vertex 4 150 Gb
PSU : 1kW seasonic platinium
Case : Corsair air 540

The system is watercooled (cpu, mobo and GPU) 1 D5 pump and 5 fans be quiet (4x140 mm and one 120).

I bought the harware one year ago exept one gpu. When i bought the second one i tested the system one month before to change for watercooling. And sometimes when i restart my compure i loose one video card 😕
I mean i cant see the card in the device manager no display on the screen (Im not in crossfire mode).

So i checked :
- Drivers uninstal and instal it worked one or two times.
- Power connection and i notice i didnt plug the EZ molex.
- BIos updates

It work fine and i watercool the system. Guess what ? My second card disapear after one week of testing !
I tried again drivers, an other psu (1200w) and many things crazy/stupid and still no change.

My cards are plugged on pci slot 1 and 2 (i read the mobo's manual after :mad:)

Ok the 2nd slot doesnt work with16x but why did it work randomly ? And why when it work i have no perfomance issue ?
I cant see differences on benchmark when i bench separately. On crossfire mode the difference is close.

I also plugged the 8 pin atx on the mobo's top and the 4 pin is free do i need to plug all or just one ?

Sorry for my english and the long story 😕

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Here the beast !

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Well now i put the card on pcie 1 and 3 and still no change im lost 😞

[HiVizMan]

As a last resort make sure your BIOS is up to date, and if you are going to flash bios please use a USB stick and EZflash2 found in the tools menu in the bios.

But one of the things that I found worked for me when I had the same problem was ensure my cards were correctly fitted, and I tried a new Crossfire bridge.

In the end I did a new OS install with the two cards fitted and that did the trick.

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I tried windows 7 and 8 nothing change it's hardware i cant see cards in the bios. I have the 1703 bios version 😕

GPU are correctly connected i tried many cmos many plug unplug.

On the asus website i saw the procedure of power reset but im not sure to do it right.

[HiVizMan]

Clear CMOS you mean.

Push the button on the back


http://assets.overclock.net.s3.amazonaws.com/2/2c/2cee2a6e_vbattach224650.jpeg

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already done nothing more i want some fuel and burn it now

[HiVizMan]

LOL I hear you but....

Mate it is pull the system out of box time.

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HiVizMan wrote:
LOL I hear you but....

Mate it is pull the system out of box time.

You didnt mean remove the harware from the case ?

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If i pull out the hardware it's to replace by intel and nvidia ><