3m hires you to determine the efciency of the

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Unformatted text preview: e 6.42 has two axes: stride and working set size. Which axis corresponds to spatial locality? Which axis corresponds to temporal locality? Practice Problem 6.19: As programmers who care about performance, it is important for us to know rough estimates of the access times to different parts of the memory hierarchy. Using the memory mountain in Figure 6.42, estimate the time, in CPU cycles, to read a 4-byte word from: A. The on-chip L1 d-cache. B. The off-chip L2 cache. C. Main memory. Assume that the read throughput at (size=16M, stride=16) is 80 MB/s. 6.6.2 Rearranging Loops to Increase Spatial Locality Consider the problem of multiplying a pair of Ò ¢ Ò matrices: ½½ ¾½ ½¾ ¾¾ ½½ ¾½ ½¾ ¾¾ ½½ ¾½ . For example, if Ò ½¾ ¾¾ ¾ , then 332 where ½½ ½¾ ¾½ ¾¾ ½½ ½½ · ½½ ½¾ · ¾½ ½½ · ¾½ ½¾ · CHAPTER 6. THE MEMORY HIERARCHY ½¾ ¾½ ½¾ ¾¾ ¾¾ ¾½ ¾¾ ¾¾ Matrix multiply is usually implemented using three nested loops, which are identified by their indexes , , and...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.

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