Crossfire Problems

[weetam]

Hi guys, I have problems with my Crossfire setup and wondering if anyone could help.

I have 2 identical 7970 Gigabyte Windforce cards and they don't work in crossfire mode. Each one works in the primary slot, but I can't get either to recognise in the secondary slot.

I've replaced the X-fire bridge for a brand new one, completely formatted reinstalled windows and updated with the latest drivers etc, changed over the PCI-E cables on the power supply (again both work in slot 1) and even went as far to replace the motherboard as I thought my secondary slot was faulty on my old board with still no luck (have the brand new motherboard installed currently).

Currently running an AsRock Extreme 4 Z77 board with a Corsair HX 850 power supply.

As far as I'm aware I've tried everything but still no luck, have I missed something? As far as I can tell the BIOS doesn't recognise the 2nd card is plugged in, never mind Windows. What's equally confusing me is that both cards run perfectly in the primary slot with no problems, have gamed easily on both with no problems.

Cheers folks

 

[tinytomlogan]

Does the board support crossfire in that slot? Try one card in the secondary slot

 

[barnsley]

The board claims to support quad crossfire and quad SLI.

Try the cards in slot 1 and 3, 2 and 4.

 

[weetam]

Yes, both boards (old one and new) support 8x/8x in Crossfire, and with both I get nothing running 1 card in slot 2 only, just a black screen

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There is only 2 PCI-E x16 slots on both boards (old one was a Sabertooth P67), the other 2 PCI-E slots are x1

 

[DrYuri]

A longshot but maybe... You had only 1 card and then you bought another one? Did you remove drivers from your system and installed second card then reinstalled the drivers? Try this if you havent

 

[weetam]

Bought both at the same time, like I say, have completely re formatted my machine with a clean install, but yes I tried this beforehand with still no joy

 

[BigDaddyKong]

I would assume you have both cards plugged into the power supply? I have those cards in my Asus board and they work great.

My first thoughts were what DrYuri posted. You need have have both cards in place when you do the driver install.

When you are in Windows, are you seeing 2 cards in the device manager?

Also, is your monitor connected to your video cards or the mobo display? Virtual MPV may mess with the second card during driver install if plugged into the mobo connector.