CPI * MIPS *10^6 = f , f频率 是一个时钟周期的倒数,表示1s可以跑的时钟周期数;CPI是一条指令需要的时钟周期数; MIPS是1s可以跑的百万条指令数量
2
- 指令集
- 计算机组织
- 系统架构
- 编译器
6
1
P1: M1执行时间10000ms > M2执行时间5000ms 所以P1在M2上更快;
P2: M1 :3ms < M2 : 6ms P2 在M1上更快
2
M1: MIPS-P1 = 200*10^6/[(10^6)*10s] = 20MIPS
MIPS-P2 = 300*10^3/(10^6)*3*10^-3 = 100MIPS;
M2: MIPS-P1 = 150*10^6/5*10^6 = 30MIPS
MIPS-P2 = 420*10^3/6*10^(-3)*10^6 = 70MIPS;
对于P2 , M1速度快, 快30MIPS (43%)
3
M1: T:1/800M = 1.25*10^-9 = 1.25ns ; CPI-P1= (10s/1.25ns)/2*10^8 = 40
M2: T:1/1.2G = 5/6 ns; CPI-P1 = (5s/(5/6ns))/1.5*10^8 = 40
7
(10*6)*MIPS * CPI = f
1
M1-MIPS = 1G/ (10^6 * 1) = 1000MIPS ;
M2-MIPS = 1.5G/(10^6 * 2) = 750MIPS ;
2
M1-CPI: (1+2+2+3+4)/5 = 2.4;
M2-CPI: (2+2+4+5+6)/5 = 3.8;
假设有N个指令 ,t1 = N*CPI1/f1 = 2.4N/1G ;t2 = N*CPI2/ f2 = 3.8N/1.5G
M1 更快; 每条指令平均快0.13(ns)
8
f1 = 1.25G ; f2 = 5/6 G; 设有N个指令
v1 = N*CPI1/f1 = 4N/1.25 = 3.2N;
v2 = N*CPI2/f2 = 2N/ (5/6) = 2.4N;
M1快 每条指令平均快0.8ns
10
S1: 10 ;
S2: 8;
S1: 5*1 + 2*2 +2*3 + 1*4 = 19; 19 /10 =1.9;
S2: 1*1 + 1*2 +1*3 + 5*4 = 10; 26 /8 = 3.25;
S1: 19/ 500M ;
S2: 26/ 500M ;
11
f =1.2G;
t =12s;
CPI:5 -> 2;
t1 = 10s;
t - t1 =2s;
N = (2s*1.2G)/(CPI-CPI1) = 0.8*10^9
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