G.Skill takes eight sticks of DDR4 to 4266 MT/s on X299
 

One way to get gobs of memory bandwidth is to ramp up the transfer rate to ridiculous levels. Alternatively, you could adopt a platform with more memory channels. In the words of Old El Paso, ¿por qué no los dos? G.Skill would like to help you along the path toward cresting the 128GB/sec memory bandwidth mark, and to assist in such endeavors, it's offering up 64-GB kits composed of eight 8-GB modules running at 4266 MT/s.

https://techreport.com/news/34429/g-...6-mt-s-on-x299