We present methods for architectural adaptation that use application-specific hardware assists and policies to provide substantial improvements in performance on a per application basis. We have used architectural customization to improve performance of the memory hierarchy and utilize network bisection for the multiprocessor architecture. We demonstrate the utility of architectural customization in efficient memory hierarchy management and memory bandwidth requirements using an application in sparse matrix manipulations. The experimental work is presented in the context of the MORPH machine that is currently being designed to provide high system performance by directly addressing memory system limitations in the current machines. Based on our preliminary results, we propose that an application-driven machine customization provides a cost effective way to achieve high performance and combat performance fragility while maintaining application retargetability across architectures.