You would have to buy a 16 Gb memory stick, so if you had four slots for the memory then
16+16+16+16 would =64 Gb. The problem finding the memory in that density on one stick.
For the most part that sort of config of memory is more likely to be used for a server motherboard with the ability to use two Cpu`s with 8 or more cores of each.
Your question, made me relook at what I was puzzeled by. I had searched for "Sabertooth" to show my wife and thinking I was looking at the X-79...NO! I was looking at AMD's 990FX...Duh! Thanks for making me look again...I am embarrassed.