Perhaps this is a known issue, and if so, I apologize. My searches online have not yielded anything in that regard. However, here is what is going on: I am unable to enable CrossFire since moving to Windows 7. XP had no issues with CrossFire, nor did Vista, but Windows 7 has been like this since the drivers moved into “legacy” state.
In fact, CCC shows my 2nd adapter as being disabled, though nothing in Windows states this, so not sure which to believe. Regardless, there is no option in CCC that I can find to even begin to turn CrossFire on/off. Perhaps this is just a glitch in the way these things are reported in CCC, but when I use Speccy (from Piriform), it shows CrossFire is disabled, so I’ve gotta believe that something is amiss here.
I'm coming here as a last resort before I move to another card entirely. This crossfire combo should be a workhorse - even by today's standards. If you need more info from me, I'll give you what I have.
Dual HD 4850 with CrossFire from Dell:
Manufacturer - ATI
Model - Radeon HD 4800 Series
GPU - RV770
Device ID - 1002-9440
Subvendor - ATI (1002)
AMD Catalyst Driver Version, and Driver History
Currently using 12.6, but was using 13.9. Both have the same behavior. 13.1 is not a valid 32-bit app according to Windows 7, so I’ve never used that one.
Windows 7 Professional 64-bit SP1
Motherboard or System Make & Model
Manufacturer Dell Inc
Model 0PP150 (Socket 775)
Chipset Vendor NVIDIA
Chipset Model nForce 650i SLI SPP
Chipset Revision A2
Southbridge Vendor NVIDIA
Southbridge Model nForce 650i SLI MCP
Southbridge Revision A3
Display Device(s) and Connection(s) Used
Samsing SyncMater P2570 via Digital input
Intel Core 2 Quad Q9550:
Cores - 4
Threads - 4
Name - Intel Core 2 Quad Q9550
Code Name - Yorkfield
Package - Socket 775 LGA
Technology - 45nm
Specification - Intel Core2 Quad CPU Q9550 @ 2.83GHz
Motherboard BIOS Version
Brand - Dell Inc.
Version - 1.0.13
Date - 5/5/2009
System Memory Type & Amount
Type - DDR2
Size - 8192 MBytes
500gb SATA in RAID configuration
Numerous slot swaps, re-cabling, & driver reinstalls (using clean method).