Asus' The Assassin supports 4-way CrossFire and 3-way SLI, but the other two models only have three PCIe x16 slots. All versions seem to have USB and SATA 3.0, two BIOS ROMs, support for 3TB+ hard drives and an on-the-fly overclocking solution. The Guerrilla seems to be the lowest-specced board and kicks the G1-Killer series off at $299. No word on what the others cost.