Would like your educated opinion on Crossfiring

Computer Type: PC/Desktop
System Manufacturer/Model Number: A blend of brains, brawn and dumb luck.
OS: Windows 7 Ultimate 64
CPU: i7 3770k OC'd 4.6 @ 1.17v, also FX 8120 & i5 miniITX
Motherboard: MSI P67A-GD80 b3
Memory: 32 gb G.Skill Sniper DDR3 10-12-12-31 @ 2133
Graphics Card: XFX Radeon 7870 2GB DDR5
Sound Card: Sound Blaster Z Series Card
Monitor(s) Displays: (2) LG LED 23" 1920 x 1080 2ms Monitors via mini d-port
Screen Resolution: 1680 X 1050 p
Keyboard: (2) Logitech Illuminated Keyboards (1) usb (1) wireless
Mouse: Logitech G700 & T-BC21 - nano nx for the laptop
PSU: EVGA modular 1000G2 80% gold rating & APC 1200 RS
Case: CoolerMaster Storm Styker
Cooling: 7 case fans 140mm & 120mm, NZXT Kraken X60
Hard Drives: Samsung 256 gb 830 SSD sata III (1) 1 tb WD Black (2) 1 tb Hitachi deskmates/sata II (2) 1 tb WD green/sata II (2) 3 tb Seagate Barracuda (1) 120 gb OCZ Vertex SS (1) Drobo 5N w/5 Seagate 3tb
Internet Speed: Basic 120mbps down
Browser: Chrome and IE 10
Antivirus: Trend Micro Titanium Max Security & Malwarebytes Premium
Other Info: 5 Noctua case fans + 3 Noctua in p/p on NZXT cooler Integrated hot swap drive bays for 2.5" Drives (2) Lite-on dvd/cd/Blu Ray optical 22X Integrated fan controller and led on/off HP Officejet Pro 8630 all-n-one Hot-swappable 3.5" hard drive bay Netgear Nighthawk router Asus USB 3 & sata 6 PCIe card Vantec IDE to sata adptr./Ultra sata adptr Lenovo L420 i5 lappy with m sata Drobo 5N advanced NAS