first one is rev 1.0 (Which i has) second one is released 1.1
I show that they have upgraded the 4pin to 8pin. As far as i know 8pin is used for high end motherboards to give more power and stability and let chance for OC.
But this is a Entry B75 Mother board. So why they have upgraded to 8pin in rev 1.1?
8pin connectors can provide more power to the CPU. It also provides more stable power.
Some motherboards need all 8pin to function, while some can work fine with just one 4pin connector even though the motherboard has 8pin slot.
8pin connectors are good for overclocking.