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kayvonf

Review questions:

• Describe the idea of hardware multi-threading.
• How is prefetching is an alternative solution to the problem that hardware multi-threading tries to solve.
• Describe a situation where prefetching may not be possible. (Hint: let's think about properties of the memory access.)
• What is the "cost" of implementing hardware multi-threading? (what additional resources are required?)
nandita
• Hardware multi-threading essentially involves swapping in a different instruction stream from a another thread for execution, to hide long memory access latencies. This keeps the idle compute units performing other useful work.
• Prefetching involves hiding memory latencies by preempting the memory access before the data is actually required.
• Prefetching data for irregular memory accesses (e.g., pointer chasing) is difficult.
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