Where is the cache on the motherboard?

With computer's data cache, (i.e., L1, L2, and L3) it's usually on the computer processor chip and not on the motherboard. The L1 cache, or system cache, is the fastest cache and is always on the computer processor. The next fastest cache, L2 cache, and L3 cache, are also often on the processor chip and not the motherboard. Some earlier computers (e.g., 486 computers) had either of these types of cache on the motherboard and had L2 cache expansion boards that could be added to the computer.

The picture below of the Intel Core i7-3960X processor die is an example of a processor chip containing six cores and the shared L3 cache.