This paper proposes a new replacement algorithm to protect cache lines with potential future reuse from being evicted. In contrast to the recency based approaches used in the past (LRU for example), our algorithm also uses the notion of frequency of access . Instead of evicting the least recently used block, our algorithm identifies among a set of LRU blocks the one that is also least-frequently-used (according to a heuristic) and chooses that as a victim. We have implemented this replacement algorithm in a detailed simulation model of a chip multiprocessor system driven by SPEC2000 benchmarks. We have found that the new scheme improves performance for memory intensive applications. Moreover, as compared to other attempts, our replacement algorithm provides robust improvements across all benchmarks. We have also extended an earlier scheme proposed by Wong and Baer so it is switched off when performance is not improved. Our results show that this makes the scheme much more suitable for CMP configurations.

Age of Computers (AoC) is a new approach to the learning activities that supplements the auditorium lectures in a computer fundamentals course with 250 students. It is a computer game that presents the students a diverse set of problems from the course topics linked to computer history. It is implemented as set of dynamic web pages retrieved from a database. A prototype was used in 2003, and the feedback is positive and a strong motivation for continuing the project. The paper describes AoC, its use and implementation.