Low to high H61 , this is nothing to say. H67, compared with H61, usually ATX version, H61 is generally M-ATX, the maximum memory capacity supported is different, H61 is generally 16GB, 67 has 32GB. H67 generally with SATA3.0 and USB3.0 Compared with H67, P67 does not have display output, which means that U's nuclear display is useless for P67. P67 can be overclocked, but only for CPU with K. The difference between Z68 and P67, starting from Z68, supports the next generation of 22NM IVY processor. Compared with the P67, there are more display output and hard disk acceleration technologies. Compared with the 6-series motherboard, the 7-series motherboard has more native USB3.0 and PCI-E3.0 (only more native USB3.0 than Z68) B75, single PCI-E3.0 slot, does not support overclocking, no hard disk acceleration technology. H77, generally a single PCI-E3.0 slot, does not support overclocking, but has hard disk acceleration technology. In fact, H77 and B75 , personally think it shoul