Z77 has support for pci-e 3.0 with ivy bridge cpus only. The other two chipsets may support ivy bridge with a bios update. Not much difference in speed; overclocking depends on the board bios adjustments. Newegg is closing out some evga boards with the older chipsets for around $50, a good deal if you don't plan on running ivy bridge cpus. The boards don't support the newer cpus; hence the low price.