Simulation of L2 Cache Separation Impact in CPU Performance

Cache memory performance is very important in the overall performance of modern CPUs. One of the many techniques used to improve it is the split of on-chip cache memory in two separate Instruction and Data caches. The current CPU organizations usually have per core separate L1 caches and unified L2 caches. This paper presents the results of simulating different CPU organizations with unified and separate L2 Instruction and Data caches using Marss-x86, a Cycle-Accurate full system simulator. The results indicate that separating the L2 cache memory provides higher overall CPU IPC. The highest improvement is 3% and is achieved in a quad-core CPU model with shared L3 cache. Analyzing the hardware costs and complications of separating L2 cache might be an interesting future work direction.