Anyone who has ever compiled a benchmark summary recognizes the futility of that exercise. Benchmark suites consisting of component programs focused on specific areas give perhaps the best measure of overall performance, but even these are flawed. These suites are roundly criticized because they don't reflect typical usage patterns and workloads, and because there is no fair way to weight the relative importance of the various components. In the future, the situation could get worse. As systems continue their march toward lower cost, higher complexity, and a more media-rich environment, processor performance issues will change dramatically and rapidly.
Benchmark efforts are unlikely to keep pace.
Already the benchmark community is far behind processors on multimedia issues. There are no good benchmarks, for example, that reveal the value of the various SIMD extensions that are now a part of all major processor architectures. But the larger issue is that the interests of processor vendors are not the same as those of consumers. Since benchmarks are highly vulnerable to manipulation, misuse, and misinterpretation, the illusion is what consumers usually get. Even though the efforts of benchmarking organizations such as ZDBOp and SPEC are honorable and well intentioned, the problems they face are bigger than the organizations are.