Adaptive Hypermedia Systems adjust the content to best suit users' personal characteristics, but rarely consider delivery performance. Performance issues are even more significant in distributed architectures such as that of an Open Corpus Adaptive Educational Hypermedia System (OAEHS). This paper introduces a Performance Oriented Adaptation Agent (POAA) that enhances OAEHS by taking into consideration not only user personal characteristics but also network delivery conditions in the content selection process. The usage of POAA is expected to bring significant delivery performance improvements in terms of learner satisfaction and learning outcome.