first rule of system building, check for bios updates. it even tells you to do so in the handbook that comes with the mb. ive built 2-3 dozen of these systems all with 970 or 990 chipsets from asus. the 0901 update was patched about december of last year although it didnt go into specifics it did enhance stability over 0701. in the burn in tests, i didnt have any trouble with steam but it was a quick run of 4 games. for those with asus mb forget the 0901 and download 1101, the newest version which has some stability fixes for the 1090t and 1100 as well.
all mb's have bios problems even with SB or IVB chips. i cant tell you how many times a customer brings in a system that they have tried to build and thinks it has a defective mb, memory slots or gpu when all was needed was the latest bios fixes. asrock gen3 is notorious for this and look at the gigabyte ud3h board didnt certify some memory with IVB, particularly gskill.
it just makes me laugh sometimes, but then again, laughter is good for the soul.