Aurora R1 and Aurora R2 Differences

The Storage, Bays, Raid, Network, Audio, Bus slots, and Power supply (525w, 875w) are the same. The differences are below -

CPU = R1 i7. R2 i3,i5,i7
Chipset = R1 Intel X58 Express. R2 Intel P55
Ram = R1 24GB DDR3 1066/1333/1600XMP. R2 16GB DDR3 1066/1333(i3/i5)/1600XMP (i7)
Chassis = R1 ALX, Non-ALX. R2 Non-ALX
PCIe x16 slots =
R1
Single video card in slot One = 16 PCIe lanes
Single video card in slot Three = 16 PCIe lanes
Dual video card Slot One & Three = 16 PCIe lanes, 16 PCIe lanes

R2
Single video card in slot One  = 16 PCIe lanes, Off
Single video card in slot Three = 1 PCIe lane, 8 PCIe lanes
Dual video card Slot One & Three = 8 PCIe lanes, 8 PCIe lanes