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Thread Starter 
Hi guys, new to the forum and I was wondering if I could get some help!

I've got 2 x EAH5850 DirectCU for my PC to crossfire but I've spent the last weektrying to get it to work. In the Catalyst Control Centre, it says that the second display adaptor is disabled and I have no option to enable crossfire at all. These are the things I have tried so far:

Checked system manager and both cards report to be working properly.
Reinstalled drivers and tried different versions (currently on 11.5)
Used driver cleaner in safe mode and reinstalled drivers
Re-seated the cards and blown dust. All firmly pressed in.
Installed the cards in different PCI-e slots
Attached one bridge and both bridges at the same time. All firmly pressed in.
Attached bridge(s) in a different direction. All firmly pressed in.
Bench marked with 3d mark 06, 3d mark 11 and Crysis with one card and both cards plugged in. The results are the same as having one card plugged in.
Updated BIOS
Updated Windows

The hardware information in CCC says:

Primary Adapter
Graphics Card Manufacturer Powered by AMD
Graphics Chipset ATI Radeon HD 5800 Series
Device ID 6899
Vendor 1002

Subsystem ID 0348
Subsystem Vendor ID 1043

Graphics Bus Capability PCI Express 2.0
Maximum Bus Setting PCI Express 2.0 x2

BIOS Version 012.020.000.005
BIOS Part Number 113-AC37600-112
BIOS Date 2010/05/28

Memory Size 3835 MB
Memory Type HyperMemory

Core Clock in MHz 725 MHz
Memory Clock in MHz 1000 MHz


Disabled Adapter
Graphics Card Manufacturer Powered by AMD
Graphics Chipset ATI Radeon HD 5800 Series
Device ID 6899
Vendor 1002

Subsystem ID 0348
Subsystem Vendor ID 1043

Graphics Bus Capability PCI Express 2.0
Maximum Bus Setting PCI Express 2.0 x16

BIOS Version 012.020.000.005
BIOS Part Number 113-AC37600-110
BIOS Date 2010/03/10

Memory Size 3835 MB
Memory Type HyperMemory

Core Clock in MHz 725 MHz
Memory Clock in MHz 1000 MHz

I have installed each card on an individual basis in each PCI-e slot with the other removed, then plugged in the second card afterwards. The second card will always display "Disabled Adaptor" in the information section of CCC no matter which slot it is in.

One card says "Maximum Bus Setting PCI Express 2.0 x2". Why is this? I have moved this card to the second pci-e slot and it says the exact same thing as if it is in the first slot. The bench marks for both cards individual score the same, so performance does not seem to be affected. Is this what is affecting the ability to crossfire because it is too slow? How do I get it to run at 16x? Is it faulty or should I roll back the drivers even further..?

I feel like I have tried everything. I have even tried ATI CF Xtension to force crossfiring but the performance is no different in 3d mark and in games. The only thing I haven't tried is taking out the BIOS battery. I don't think it's anything to do with the BIOS because the PCI-e speed of the card is always at x2 in both slots.

Both cards work perfectly fine individually, however I cannot seem to get them to work together in crossfire. The secondary card is always stone cold after benchmarks so it's obviously it's not being utilised. I really hope somebody can help! It's so frustrating!

PC specs:

Intel i930 2.8ghz
2 x EAH5850 DirectCU
6GB Corsair DDR3 1600MHz XMS3 CL9(9-9-9-24) 1.65V
Asus P6X58D-E X58
Corsair 650W TX Series PSU
64bit Windows 7 Ultimate 6.1.7601 SP1 Build 7601