Although most of the hashing computation is done on the R909, the device does use some CPU computational power to run cgminer. In our tests here’s the number of R909s that can be run on various computers Raspberry pi4: 2  PC with 6th gen Core i3 CPU: 4 PC with 9th gen Core i5 CPU: 5 PC with 10th gen Core i5 CPU: 6 PC with 12th gen Core i5 CPU: 9