At this point, neither of them... Either wait for the chipset bioses to mature or look at another platform, 100% stability is ONLY achievable by "Luck" or "patience" at this point and unless you're and extremely lucky individual you'll need some OCing skillz even in order to stabilize stock speeds.
So these boards arnt even stable @ stock? what the F*** lol! whats the X48 chipset like? id consider one of these as i wont be going SLI ... i did it once and its just too expensive and you dont really see a HUGE improvement
Asus Maximus V Gene BIOS 1204
Intel I7 3770K/Corsair H100
2x4GB Corsair Dominator GT 1866 C9
Asus GTX 680
Creative XFI Titanium
2x 128GB OCZ Vertex 4 SSD in RAID 0
Liteon Blu ray
Corsair HX 850W
NZXT Phantom Red
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