I went on the gigabyte site and did a compare of the two: http://www.gigabyte.com/products/comparison/list.aspx?c.... They are only small differences like the P has a better sound card and seems to be better than the other mobo. Overall they wont make the motherboard faster, its just really the amount of the features it has that really changes. Take the one which fits your needs but if the price difference is small i would just go with the P, seems like a good choice.
Hope this helps.