The Platform - 790FX Chipset
The AMD Phenom processor is only the first part of a three part platform message that AMD is trying to present. The second part was the new AMD Radeon HD 3800 series of graphics, a new GPU that we got very familiar with last week. The third part is a new chipset, the second from the new AMD, known as the AMD 790.
AMD 790FX Chipset
Much to NVIDIA's dismay, AMD is going with a chipset very similar in naming scheme to their own "700-series" and is actually going to be first to market with quite a few motherboards that have been ready for months. Being forced to sit on the boards until the CPU launch, you should find solutions from MSI, Gigabyte and Asus immediately.
The 790FX chipset is the first in a series of 700 options that will continue on with an integrated option with DX10 support and a notebook chipset as well that AMD seems very confident will bring their market share back in that area.
There are actually three different chipsets in the fold today starting with the high-end 790FX that will support quad-graphics cards, though not necessarily four dual-slot cards (depends on the motherboard manufacturer's implementation). The 790X chipset will support at least dual graphics cards for CrossFire support and the 770 chipset is the budget option for single graphics card support. All three chipsets have native PCIe 2.0 support; though with varying numbers of lanes obviously.
Here is a quick diagram of the 790FX features -- notice that there are two physical x16 PCIe 2.0 slots that are divided up between four graphics cards. When two GPUs are installed they will both run at x16 though if all four cards are installed they will run at x8 each thanks to some logic built into the chipset. There are 6 more lanes of PCIe 2.0 support for other accessories, too. The two lower end chipsets will actually only have a single x16 PCIe 2.0 connection on them, split between two cards for CrossFire support.
MSI K9A2 Platinum using the AMD 790FX chipset - Review coming soon!
For now, the SB600 south bridge will be used on all the AMD 790FX motherboards until sometime in Q1 when the new SB700 south bridge is released. We don't have a lot of information about that yet though the advancements are going to be minor from what I have heard.
One of the big new features for the AMD 790FX chipset and Phenom platform in general is their new Overdrive software. Similar in theory to what NVIDIA's nTune application was supposed to do, it is meant to be used to overclock and tweak your system in Windows and with minimal trouble for beginners.
The AMD chipsets (and formerly the ATI chipsets) have continually had a big advantage when it comes to power consumption - the 480X and 690G sipped power compared to what NVIDIA has offered.
AMD is also hoping that their aggressive pricing on the 700-series chipsets will put their boards at a price advantage to NVIDIA's and Intel's own chipsets. While the motherboard vendor ultimately will decide how expensive and extravagant their products are, it's been seen in the past that AMD/ATI chipset boards have simply cost less.