Hi,
I justrecently crossfired my system (Specs below)and on the first try I found the black death was more fluid than I had ever seen it before.Free flight over London was the best I ever saw too.This was running on Retail Patch v 1.01.14550 .
Because of the closeness of my two graphics cards the top one is getting hot not being able to draw ebough air through the fan due to the second cards pcb being 12mm from the intake .Having the rest of the system watercooled I have ordered two full size Waterblocks which will irradicate the problem.
On the release of the 1.01.14588 patch I now find all is back to a studdery mess so I cleared every trace of COD off the system and did a clean instal.
Regardless of what settings I have set the game or the Graphics cards to it
ramains studdery.Seems like the little patch has messed something up.

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System Specification
O/S 64bit Windows 7 Home Premium
Processor: AMD Phenom(tm) II X6 1100T Processor
Speed : 3.6GHz
Mainboard : Gigabyte GA-890FXA-UD5
BIOS : Award (Phoenix) F6 11/24/2010
Bus(es) : ISA X-Bus PCI PCIe USB FireWire/1394
Total Memory : 8GB DIMM DDR3(2x4GB DIMM PC12800U)
Chipset Model : ATI (AMD) RD890 single slot GFX Hydra
Front Side Bus Speed : 201MHz
Video Adapter : 2x Saphire Vapour X OC 1024 MB GDDR5 Core MHz875 Memory1250 MHz
OCZ-VERTEX2 3.5 (240GB, SATA300, SSD) :
WDC WD5001AALS-00L3B2 (500.1GB, SATA300, 3.5", 7200rpm, 32MB Cache)
WDC WD1500HLFS-01G6U1 (150GB, SATA300, 3.5", 10000rpm, 16MB Cache)
hp DVD-RAM GH40L (SATA150, DVD+-RW, CD-RW, 2MB Cache)
Steel series USB soundcard.
1000Watt power supply
ATI 11.5 Drivers