Final answer:
For a 64-element vector load with a stride of 1, it will take 19 cycles to complete. With a stride of 32, assuming worst-case bank conflicts, it will take 390 cycles.
Step-by-step explanation:
The question asks about the time it takes to complete a 64-element vector load from memory with different strides, considering there are 8 memory banks, a bank busy time of 6 clocks, and a total memory latency of 12 cycles.
When loading a vector with a stride of 1, each element is located in consecutive memory locations. Given 8 memory banks, the memory banks can be accessed in parallel. Therefore, once the initial latency is paid, a new bank can be accessed every clock cycle. The number of cycles to load the vector can be calculated as the sum of the latency (to load the first element) and the time to load the remaining elements. Since there are 64 elements and 8 elements can be loaded in parallel (one per bank), it will take 12 cycles (initial latency) + (64/8 - 1) cycles = 12 + 7 = 19 cycles to complete the load.
With a stride of 32, the pattern changes as consecutive elements are located far apart. This likely means that each element is in a different bank, but depending on the actual memory address mapping to banks, there can be bank conflicts. Assuming the worst-case scenario where each load after the first incurs the bank busy time, we would have 12 cycles for the first element, plus 6 cycles for each subsequent element. Therefore, the total load time would be 12 + 6 * (64 - 1) = 12 + 6 * 63 = 390 cycles.