[jokoon]

How do you measure performance per watt? FLOPS/watt? I don't think FLOPS is worthy measure of chip performance, since it doesn't take the L1/L2/L3 cache size into account.

Are there performance benchmarks that are designed to measure server application performance?

[wmf]

There are plenty of server performance benchmarks and even one for power efficiency: https://www.spec.org/power_ssj2008/

Google probably has a whole team internally to benchmark their own applications on different hardware.