Jason Clark & Ross Whitehead, July 17th, 2007
Power is on everyone's mind these days and rightfully so. The cost of operating and cooling the average server is certainly not cheap, and is on the rise year over year. The question is whether the CPU is the component under the hood that is utilizing the majority of total system power or not. The answer to that question should be clear: the CPU is just a piece of the puzzle. Memory, fans, chipset, drives, HBAs, etc. all play a role in utilizing power.
AMD is clearly the leader when it comes to performance per watt using the workloads in this article. What is interesting to note is that AMD's advantage isn't at the processor level, but instead it's related to the fact that they don't use fully buffered DIMMs. Obviously, the measurements we took of each component aren't precise - it's just about impossible to do that (at least without sophisticated equipment). However, we can safely draw the conclusion that there is a lot more to power consumption than the CPU itself.