Multiple graphics card setups are becoming increasingly popular given the improvement in driver quality and actual performance scaling in games. That just makes things all the more enticing to push into the triple and quad GPU territory.
MSI’s Big Bang X58 XPower Motherboard can handle your many graphics card needs while also providing USB3 support and advanced on-board audio functionality. Guru3D has the review:
The MSI X58 based Big Bang Xpower comes equipped with six memory slots rated at even DDR3-2200 (overclocked) and six (!) PCI-Express x16 slots that thus provide upto 2-way SLI and 4-way CrossFireX support. You’ll get eight SATA II ports and then two another SATA III (6 Gbit) ports and two eSATA ports as well. Obviously the board comes with dual Gigabit Ethernet and nifty features like V-Check points, Power, Reset, and Clear CMOS buttons, and a FireWire connector.
Yes the feature richness will cost you but you’re getting what you pay for with this board.