[理工] [計組]-cache

[gn00618777 (123)]

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= =?

--
※ 發信站: 批踢踢實業坊(ptt.cc) 
◆ From: 122.124.200.154
→ ieric:我列的是:1.2+1.1(0.05*8+0.05*0.2*60)
→ gn00618777:我不喜歡用課本那種列式，我覺得好難懂喔
→ gn00618777:如果用我這方法列1.1要怎麼用上？
→ taitin:你的式子就好整個加1.1 ，或者是每項都加1.1也一樣
→ taitin:另外我怎麼覺得一樓的式子怪怪的
推 muwalker:列的跟一樓一樣~
→ taitin:阿..我看懂了XD..一樓沒錯..原來是一個指令1.1memory
→ taitin:問一下1.1不用乘1.2嗎？
→ taitin:噗..我知道為什麼了XD
→ taitin: 0.95*1.2+0.05*0.8(1.2+8*1.1)+0.05*0.2(1.2+(8+60)*1.1)
→ taitin:原po可以這樣列