CS SUB 我们讨论点具体的题目吧

ilovelzwUID: 2315388

30.    Changing a certain cache from direct mapped to two-way set-associative caused the hit ratio measured for a certain set of benchmarks to improve from 0.91 to 0.96, with TC = 20 ns, and TM = 70 ns. What is the speedup, assuming no change in TC from the set-associative multiplexer? Speedup is the ratio of the time to complete a process without the improvement to the same process with the improvement.
             (A) 1.00   (B) 1.11   (C) 0.89   (D) 0.96   (E) 1.89


这个 TM  TC  是什么意思? 是什么的缩写?

这是一道关联计算机体系结构中 计算机性能计算的问题  这题该怎么做呢??


大家也别光顾报名了    还是讨论一点具体的题目吧

uiagUID: 2314602

TC--大概指的是 Cache access time
TM--大概指的是 Memory access time
这道题我算的是1.11,不知道对不对。
我也要考cs sub，可以交流一下吗？

jameswang99UID: 2241610

Before the improvement, the total time to service all requests is
91*2+9*7=245
After the improvement, the total time to service all requests is
96*2+4*7 = 220

245/220 ~= 1.11

So the answer should be B.

我的email 是 wcon006@gmail.com
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[ 本帖最后由 jameswang99 于 2007-7-25 13:33 编辑 ]