作者gn00618777 (123)
看板Grad-ProbAsk
標題[理工] [計組]-cache
時間Mon Feb 15 15:10:03 2010
大同資工97計組
A computer system has L1 and L2 caches. The local hit rates of L1 and L2
are 95% and 80%,respectively. The miss penalties are 8 and 60 cycles.
Assuming a CPI of 1.2 without any cache miss and average of1.1 memory
access per instruction, what is the effect CPI after cache missses are
factored in ?
我列的式子
CPI= 0.95*1.2+0.05*0.8(1.2+8)+0.05*0.2(1.2+8+60)
題目給的1.1我不知到要怎麼用上= =?
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1F：→ ieric:我列的是:1.2+1.1(0.05*8+0.05*0.2*60) 02/15 15:21
2F：→ gn00618777:我不喜歡用課本那種列式，我覺得好難懂喔 02/15 15:24
3F：→ gn00618777:如果用我這方法列1.1要怎麼用上？ 02/15 15:27
4F：→ taitin:你的式子就好整個加1.1 ，或者是每項都加1.1也一樣 02/15 16:16
5F：→ taitin:另外我怎麼覺得一樓的式子怪怪的 02/15 16:17
6F：推 muwalker:列的跟一樓一樣~ 02/15 16:19
7F：→ taitin:阿..我看懂了XD..一樓沒錯..原來是一個指令1.1memory 02/15 16:21
8F：→ taitin:問一下1.1不用乘1.2嗎？ 02/15 16:26
9F：→ taitin:噗..我知道為什麼了XD 02/15 16:33
10F：→ taitin: 0.95*1.2+0.05*0.8(1.2+8*1.1)+0.05*0.2(1.2+(8+60)*1.1) 02/15 16:33
11F：→ taitin:原po可以這樣列 02/15 16:33