و عليكم السّلام و رحمة الله و بركاته ...
My dear, right now both of GIGABYTE & ASUS are two of the best companies in Computer Components, Parts, ... etc .
but the answer of your question depends on the model of the motherboard for any company
in short words : i can give you a board by GIGABYTE that is more much powerfull than another from ASUS, on the other hand, i can give an ASUS board more much powerfull than another one by GIGABYTE .
All depends on the boards model.