IPKB: A New Metric for Evaluating Cache Replacement Policies

Nowadays replacement policies draw the attention of researchers. These policies have a direct impact on the cache miss rate and consequently on the performance and power consumption. The hardware overhead grows as the complexity of cache replacement policies increase which results in energy penalties. In this article, we introduce IPKB (Improvement Per Kilo Byte) as a touchstone for replacement policies and then use this new metric to evaluate recent common and credible replacement policies. IPKB indicates both miss rate and hardware overhead, the latter is a better representative of energy consumption. We show that using our metric, the policies with higher miss rate improvement were not the best policy because of their massive hardware overheads.