You are designing a write buffer between a write-through L1 cache and a write-back L2 cache. The L2 cache write data bus is 16 B wide and can perform a write to an independent cache address every four processor cycles.

a. How many bytes wide should each write buffer entry be?

b. What speedup could be expected in the steady state by using a merging write buffer instead of a nonmerging buffer when zeroing memory by the execution of 64-bit stores if all other instructions could be issued in parallel with the stores and the blocks are present in the L2 cache?

c. What would the effect of possible L1 misses be on the number of required write buffer entries for systems with blocking and nonblocking caches?