The metric work done per clock is not a useful one. Efficiency, i.e. energy spent per work done is a lot better. The latter, however, is heavy influenced by the

The metric work done per clock is not a useful one. Efficiency, i.e. energy spent per work done is a lot better. The latter, however, is heavy influenced by the process node - so comparing different processes when it comes to efficiency is rather futile. Higher IPC may mean inability to clock higher. In applications where work done per time matters (say games, HFT) it also doesn't provide much.