Inside Intel Nehalem Microarchitecture

Memory Cache

On the cache memory
side Intel will use the same cache arrangement AMD is using on their Phenom CPUs, i.e., individual L2 caches for each core and a shared L3 memory cache. Each L2 memory cache will be of 256 KB and the L3 cache will be of 8 MB, at the least for the first models to be launched (Intel may launch Nehalem-based Xeon CPUs with more cache). L1 cache remains the same as Core 2 Duo (64 KB, 32 KB for instructions and 32 KB for data).

Core 2 Duo processors have only one L2 memory cache, which is shared among all CPU cores, but quad-core CPUs from Intel like Core 2 Quad and Core 2 Extreme have two L2 caches, each one shared by each group of two cores. For a better understanding we summarize the available cache architectures on Figures 3 and 4.

Figure 3: A comparison between cache architectures.

Figure 4: A comparison between cache architectures.