The ASUS Crosshair IV Extreme is the most hardcore mobo based on AMD 890FX chipset. It has 5 PCIe full length slots that supports AMD 3 way and Quad CrossFireX. It has has a dual bios with an overclocker friendly feature. On board you will also find the ROG Connect and RC Bluetooth allow you to control the main system from the external device.
Other than the North bridge AMD 890FX chipset, there is a Lucid chip right next to the chipsets. With Lucid, Crosshair IV Extreme gives you the flexibility to support multiple GPUs from both AMD (ATI) and NVIDIA.
Lucid’s Hydra chips removes the barrier of combing performance of two or three graphics cards. With it, you can run in the A mode for a combination of ATI GPUs, the N mode for Nvidia GPUs and the X mode that combines the power of ATI and Nvidia chips. Notice the closeness of the red PCIe slots, so you might want to consider single slot graphics cards instead of double as this will give you more PCIe slots for more graphics cards.
The motherboard also comes with a PCI-E graphics switch, which means that you can switch between graphics cards to check problems with each one individually.
