CDC 1600 & 6600 logic & power densities
This graph taken from Jim Thorntonís book on the Design of A Computer, The Control Data 6600 compares the 6600 with the 1604. It made 5 times more logical decision per cubic foot. And the power per logical decision was half. Together this gives a factor of 10. Still the machine was much larger because of the parallelism so there were many more decisions to make.
The impressive thing about the machine was that it used a 10 Mhz clock which is defined to be a minor cycle. The clock had 4 phases, so a lot could be done in a minor cycle especially since combinatorial logic was used extensively.
Floating point adds and multiplies took only 400 and 1000 nanoseconds or 4 and 10 minor cycles respectively. In the PDP 6 we we built that used a 10 Mhz clock, the add time varied from 400 to 3000 nanoseconds. So I was very impressed with the speed.