Thought process skills for SPE

Dr Neil Gunther rightly mentions that hardware systems are increasingly becoming more&more commodity "black boxes" with lot of hidden complexities in each subsystem(cpu,memory,disk and network subsystems) and the onus is on the performance resultant to understand the Application atleast to get the basics if not fully for software performance&scalability. William Louth(JXInsight CTO) has also been recently stressing the same indirectly when he was presenting QoS concepts for Applications in cloud ("Applicaton is the network"). No doubt this would mean a little more steeper learning curve for anyone trying to bring about significant results in performance,scalability in shortest possible time but any such application centric efforts(be it in knowledge acquisition,understanding runtime behavior from Software performance engineering perspective)  would be more beneficial in terms of cost-benefit analysis.A glassbox if not a whitebox testing holds the key and right choice/freedom in choosing the tools/models for experienced people saves time&cost in long run to do the right/relevant work.