http://www.edn.com/design/systems-design/4368983/Future-of-computing--Part-3-The-ILP-Wall-and-pipelinesWhat Does It All Mean?
The implementation of extensive CPU parallelism combined with Denard Scaling and Moore's Law process enhancement delivered nearly half a century of unprecedented productivity growth directly tied to computer performance.
However that parallelism has reached an impenetrable wall of logical complexity and power consumption that renders further improvement incremental at best and may actually cause execution speeds to regress.
The modern microprocessor era kicked off with the penetrating 1980 RISC processor analysis by Patterson and Dave Ditzel.10 The insights of that study directly led to the SPARC CPU and indirectly to MIPS, the Pentium, and all of its descendants.
However the latest edition of Patterson's book is definitely pessimistic:
"...the exploitation of ILP (instruction level parallelism) - namely, speculation - is inherently inefficient."
"...we have reached - and, in some cases, possibly even surpassed - the point of diminishing returns in our attempt to exploit ILP."
"...lower CPIs (clocks per instruction) are likely to lead to lower ratios of performance per watt, simple due to overhead."
"The complexities of implementing these capabilities is likely to mean sacrifices in the maximum clock rate."
"...the widest-issue processor...is the Itanium 2, but it also has the slowest clock rate, despite the fact that is consumes the most power!"
"...modern microprocessors are primarily power limited."
To be properly and profoundly depressed regarding the state of computing, an engineer must read the recent works of Patterson, Kogge, Sterling, Dobberpuhl, Moore, Yelick, Colwell, or the several hundred or so lesser lights. These are some of the smartest individuals of the planet, and they essentially predict the end of computer improvement.
Patterson said it best in his recent interview with the New York Times regarding yet another dismal study. "I’m pretty sure it means we need to innovate, since we don’t want to die!"