AM3 processors such as the Phenom II X4 955 will work on this board, while the Phenom II X4 940/920 processors won't.
Although this is the same AMD 790FX north bridge chip released back in 2007, the SB750 south bridge came out last year. This 55nm chip supports 12 USB 2.0 ports, a single IDE channel and 6 SATA ports boasting support for RAID 0, 1, 5, 0+1.
AMD has got away not having to upgrade the 790FX chipset to support the AM3 platform because all Phenom processors use an on-die memory controller. New AM3 processors like the Phenom II X4 955 can handle either DDR3 or DDR2 memory, but they are forced into DDR3 when using the AM3 platform.
The Crosshair III Formula supports up to 16GB of dual-channel DDR3 memory in a range of speeds up to DDR3-1600. The board carries four DIMM slots total, and while DDR3-1066/1333 is officially supported DDR3-1600 can be reached through overclocking.
The board has two PCI Express x16 slots, three PCIe x1 slots and a single PCI slot. The Crosshair III Formula can take advantage of ATI's CrossFireX using the full PCIe x16 bandwidth across both slots. As mentioned before, there's no SLI support present in the Crosshair III Formula.
Asus has added a separate soundcard as part of the package. This has been the case with many of the latest high-end Asus motherboards, where they have 'saved' valuable PCB real-estate by going with a add-in soundcard-like approach.
What they call the SupremeFX X-Fi is the latest in their SupremeFX range. This small PCI Express x1 card features an Analog Device AD2000B HD Audio codec, supporting output for up to 8 channels and Creative's EAX 4.0HD API. According to the ADI website, the AD2000B chip features six ADCs with 96kHz at 95dB, simultaneous recording of three stereo channels, support for quad microphone arrays, independent sample rates from 8kHz to 96kHz, and 16, 20, and 24-bit PCM resolution.
The storage capabilities of the Crosshair III Formula are surprisingly basic with just five onboard SATA ports, plus a sixth port mounted on the I/O panel to provide eSATA (SATA On-the-Go). There is a single UltraDMA 133/100/66 port for up to two Parallel ATA devices. Ideally we like to have at least eight SATA ports on-board with an additional eSATA port on a high-performance platform.
IEEE1394a (Firewire 400) support is on the menu, offering bandwidth suitable for data-intensive applications like digital video (DV), professional audio, and external hard drives. The Crosshair III Formula provides two 1394a ports due to the inclusion of the VIA VT6308P PCI IEEE-1394 Firewire controller.
Unlike many high-end motherboards there is a single Gigabit LAN controller featuring AI NET 2. The Crosshair III Formula gets its Gigabit LAN support from the Realtek RTL8111C controller which uses the PCI Express bus. This means we should see maximum throughput when testing the network performance of this motherboard.