Figure 6 shows the normalized area of hybrid cache at different sizes. This area consists of STT-RAM, SRAM and area overhead of peripherals containing swap memory, data splitting (counter & comparator), and EB flag bit and two bit Cnt in the tag store. We used Synopsis Design Compiler to determine the area overhead of the parallel counter and comparator in 45-nm technology. The area of added flag and Cnt bits is estimated by modifying the NVsim source code. For 5T cell we draw the layout of the cell in 45-nm rule and added the features to NVsim tool. As results show, the area efficiency of the proposed caches improves for large memory sizes. We observe that 768KB STT/6T and STT/5T have 16.9% and 20.3% area efficiency with respect to the SRAM cache.