Is this saying that this wouldn't scale as the number of processors goes up? Is this any less scalable than the basic directory system described earlier?
@thomasts as the number of processors increase, so would the total amount of cached data. If we had 1000 processors, suddenly we now need to keep track of 1GB worth of cache lines. SRAM is expensive.
I think it scales the same as the basic directory system, just with a different constant (size of cache instead of size of local memory).
Also one of the flat schemes.