> summary(cpu$READ + cpu$WRITE) Min. 1st Qu. Median Mean 3rd Qu. Max. 0.616 1.717 2.750 4.555 6.140 24.030
I believe you have the calculation correct except that the 19.2 GB/s is per socket.
So the total max theoretical bandwidth is 38.4 GB/s.
How close you can get to this peak bw depends on all DIMM slots being occupied and the bandwidth benchmark test being used.