2 1201 A cache acts as a filter. For example, for every 1000 instruc- sses may exhibit lowe locality that they cannot be serviced by a 2 MB cache. The 2 MB cache is said to have an MPKI (misses per thousand instructions) of 20, and this will be largely true regardless of the smaller caches that precede the 2 MB cache. Assume the fol- lowing cache/latency/MPKI values: 32 KB/1/100, 128 KB/2/80, 512 KB/4/50, 2 MB/8/40, 8 MB/16/10. Assume that accessing the off-chip memory system requires 200 cycles on average. For the following cache configurations, calculate the average time spent accessing the cache hierarchy. What do you observe about the downsides of a cache hierarchy that is too shallow or too deep? a. 32 KB L 8 MB L2; off-chip memory b. 32 KB LI; 512 KB L2; 8 MB L3; off-chip memory c. 32 KB LI; 128 KB L2; 2 MB L3; 8 MB L4; off-chip memory