Found this: (here...
http://forums.bit-tech.net/showthread.php?t=214344 )
"There's only one true AM3+ chipset, and that's that 9XX series. The 8XX series boards that support AM3+ only do so because they have a modified BIOS, not because they were meant to support it to begin with. The 9XX boards also use a different system for power regulation, so if you're planning on overclocking, the 8XX boards may not take kindly to it. The 9XX chipset also features a faster HyperTransport, 3.1 vs 3.0.
As for a breakdown of the chipset, it goes like this:
Chipsets with no designation do not supposrt Crosfire or SLI.
G chipsets have onboard graphics, typically featuring a PCI-e x16 slot.
M chipsets have onboard graphics, typically featuring a PCI-e x16 slot. These are designed for mobile processors
GX chipsets have onboard graphics, typically featuring a PCI-e x16 slot. Supports Crossfire by also utilizing onboard graphics.
X chipsets also have PCI-e x16 slots, but typically feature two of them. Supports Crossfire.
FX chipsets also have PCI-e x16 slots, but typically feature four of them. Supports Crossfire. Also the only chipset that supports quad graphics."