CPU性能衡量参数-主频，MIPS，CPI，时钟周期，机器周期，指令周期
CPU性能衡量参数-主频，MIPS，CPI，时钟周期，机器周期，指令周期
1，主频
主频 = 时钟频率，它是指CPU内部晶振的频率，常用单位为MHz，它反映了CPU的基本工作节拍;
时钟频率又称主频，它是指CPU内部晶振的频率，常用单位为MHz，它反映了CPU的基本工作节拍;
2，时钟周期
时钟周期 t =1/ f; 主频的倒数
3，机器周期
机器周期 = m*t ;一个机器周期包含若干个时钟周期
4，指令周期
指令周期 = m*t*n; 执行一条指令所需要的时间，一般包含若干个机器周期
5，CPI
CPI = m*n; 平均每条指令的平均时钟周期个数
指令周期 = CPI×机器周期 = n（CPI=n）×m×时钟周期=nm/主频f, 注意指令周期单位是s或者ns，CPI无量纲
参考：https://en.wikipedia.org/wiki/Cycles_per_instruction
6，MIPS(MillionInstructions Per Second）
MIPS = 每秒执行百万条指令数 = 1/（CPI×时钟周期）= 主频/CPI
MFLOPS 每秒百万浮点运算次数。
表示秒钟所能执行的指令条数，对于微型计算机可用CPU的主频和每条指令的执行所需的时钟周期来衡量。
包含关系：指令周期通常用若干个机器周期来表示，在机器语言中，使用执行一条指令所需要的机器周期数来说明指令执行的速度。而机器周期又包含若干个时钟周期。时钟周期是最基本的操作单位。
参考： https://en.wikipedia.org/wiki/Instructions_per_second
注意：计算机的运算速度一般用每秒钟所能执行的指令条数来表示。由于不同类型的指令所需时间长度不同，因而运算速度的计算方法也不同。例如，根据不同类型的指令出现的频度，乘上不同的系数求得统计平均值，得到平均运算速度。这种方法用MIPS(Millions of Instruction Per Second)作单位，即每秒百万条指令。
又如，直接给出CPU的主频和每条指令的执行所需的时钟周期。周期一般以MHz为单位。主频即计算机的时钟频率，它在很大程度上决定了主机的工作速度。例如，型号为486DX-133的微型计算机，表明它的CPU型号为486，DX为含浮点处理器，数字133的含义是主频为133MHz。
题： 若某处理器的时钟频率为500MHz，每4个时钟周期组成一个机器周期，执行一条指令需要3个机器周期，则该处理器的一个机器周期▁8▁ns，平均执行速度为▁42▁MIPS
解析如下：
时钟周期T等于主频的倒数，即T=1/500MHz=1/（0.5×10的9次方Hz）=2 ns，机器周期等于4个时钟周期即=4T=4×2 ns=8 ns，每条指令的时钟周期数CPI=3×4=12，则平均速度为：f/（CPI×10的6次方）=（500×10的6次方）/（12×10的6次 方）=500/12=41.6≈42MIPS.计算主频的倒数时要注意把主频的MHz换算成Hz即500后面加6个0=500×10的6次方=0.5×10的9次方，1/10的9次方 Hz=1ns
每条指令的时钟周期数CPI=3×4=12，执行一条指令需要3个机器周期数，一个机器周期包含4个时钟周期，所以CPI=3×4=12，这里计算 的都是周期的个数，和具体的时间ns纳秒没有关系，若带上具体的时间，一个时钟周期T=2ns，一个机器周期就是2×4=8ns，执行一条指令需要三个机 器周期得出执行一条指令需要的具体时间为3×8=24ns，执行每条指令的需要的时钟周期数CPI换句话说就是把执行每条指令需要的时间24ns换算成时 钟周期个数表示，为多少个时钟周期个数?时钟周期是最基本的时间操作单位，500MHz主频的处理器一个时钟周期为2ns，24ns等于多少个时钟周期？24/2=12个时钟周期，即那一句：“每条指令的时钟周期数CPI=12”。
另一个例子：
A 40-MHzprocessor was used to execute a benchmarkprogram with the following instruction mix and clockcycle count:
| Instruction type |
Instruction count |
Clock cycle count |
| Integer arithmetic |
45000 |
1 |
| Data transfer |
32000 |
2 |
| Floating point |
15000 |
2 |
| Control transfer |
8000 |
2 |
Determine the effective CPI, MIPS rate, and execution time for thisprogram.
Total instructioncount = 100000.
CPI = (45000*1 +32000*2 + 15000*2 + 8000*2)/100000 = 155000/100000 = 1.55.
MIPS = clockfrequency/(CPI*1000000) = (40*1000000)/(1.55*1000000) = 25.8.
Therefore:
Execution time (T)= CPI*Instruction count*clock time = CPI*Instruction count/frequency =1.55*100000/40000000 = 1.55/400 = 3.87 ms.
IPS演进时间表
| 处理器 |
IPS |
IPS/MHz |
年份 |
来源 |
| 笔算(用于比较) |
0.0119 IPS |
n/a |
1892 |
[1] |
| Intel 4004 |
92 kIPS at 740 kHz[2] |
0.124 |
1971 |
|
| IBM System/370 model 158-3 |
1 MIPS |
1 |
1972 |
|
| Intel 8080 |
640 kIPS at 2 MHz |
0.32 MIPS/MHz |
1974 |
|
| VAX-11/780 |
500 kIPS |
0.5 |
1977 |
|
| Motorola 68000 |
1 MIPS at 8 MHz |
0.125 MIPS/MHz |
1979 |
|
| Intel 286 |
2.66 MIPS at 12 MHz |
0.22 MIPS/MHz |
1982 |
[3] |
| Motorola 68020 |
4 MIPS at 20 MHz |
0.2 MIPS/MHz |
1984 |
|
| ARM2 |
4 MIPS at 8 MHz |
0.5 MIPS/MHz |
1986 |
|
| Motorola 68030 |
11 MIPS at 33 MHz |
0.33 MIPS/MHz |
1987 |
|
| Intel 386DX |
8.5 MIPS at 25 MHz |
0.34 MIPS/MHz |
1988 |
|
| Motorola 68040 |
44 MIPS at 40 MHz |
1.1 MIPS/MHz |
1990 |
|
| Intel 486DX |
54 MIPS at 66 MHz |
0.818 MIPS/MHz |
1992 |
|
| Motorola 68060 |
88 MIPS at 66 MHz |
1.33 MIPS/MHz |
1994 |
|
| Intel Pentium Pro |
541 MIPS at 200 MHz |
2.705 MIPS/MHz |
1996 |
[4] |
| ARM 7500FE |
35.9 MIPS at 40 MHz |
0.897 MIPS/MHz |
1996 |
|
| PowerPC G3 |
525 MIPS at 233 MHz |
2.253 MIPS/MHz |
1997 |
|
| Zilog eZ80 |
80 MIPS at 50 MHz |
1.6 MIPS/MHz |
1999 |
[5] |
| Intel Pentium III |
1,354 MIPS at 500 MHz |
2.708 MIPS/MHz |
1999 |
|
| Freescale MPC8272 |
760 MIPS at 400 MHz |
1.9 MIPS/MHz |
2000 |
[6] Integrated Communications Processors |
| AMD Athlon |
3,561 MIPS at 1.2 GHz |
2.967 MIPS/MHz |
2000 |
|
| AMD Athlon XP 2400+ |
5,935 MIPS at 2.0 GHz |
2.967 MIPS/MHz |
2002 |
|
| Pentium 4 Extreme Edition |
9,726 MIPS at 3.2 GHz |
3.039 MIPS/MHz |
2003 |
|
| ARM Cortex A8 |
2,000 MIPS at 1.0 GHz |
2.0 MIPS/MHz |
2005 |
[7] |
| AMD Athlon FX-57 |
12,000 MIPS at 2.8 GHz |
4.285 MIPS/MHz |
2005 |
|
| AMD Athlon 64 3800+ X2 (Dual Core) |
14,564 MIPS at 2.0 GHz |
7.282 MIPS/MHz |
2005 |
[8] |
| Xbox360 IBM "Xenon" Triple Core |
19,200 MIPS at 3.2 GHz |
2.0 MIPS/MHz |
2005 |
|
| PS3 Cell BE (PPE only) |
10,240 MIPS at 3.2 GHz |
3.2 MIPS/MHz |
2006 |
|
| AMD Athlon FX-60 (Dual Core) |
18,938 MIPS at 2.6 GHz |
7.283 MIPS/MHz |
2006 |
[8] |
| Intel Core 2 Extreme X6800 |
27,079 MIPS at 2.93 GHz |
9.242 MIPS/MHz |
2006 |
[8] |
| Intel Core 2 Extreme QX6700 |
49,161 MIPS at 2.66 GHz |
18.481 MIPS/MHz |
2006 |
[9] |
| P.A. Semi PA6T-1682M |
8,800 MIPS at 2.0 GHz |
4.4 MIPS/MHz |
2007 |
[10] |
| Intel Core 2 Extreme QX9770 |
59,455 MIPS at 3.2 GHz |
18.580 MIPS/MHz |
2008 |
[11] |
| Intel Core i7 Extreme 965EE |
76,383 MIPS at 3.2 GHz |
23.860 MIPS/MHz |
2008 |
[12] |
| AMD Phenom II X4 940 Black Edition |
42,820 MIPS at 3.0 GHz |
14.273 MIPS/MHz |
2009 |
[13] |
Timeline of instructions per second
| Processor |
Dhrystone MIPS |
D IPS / clock cycles per second |
D IPS / clock cycles per second / Cores per die |
Year |
Source |
| Intel 4004 |
92 kIPS at 740 kHz |
0.1 |
0.1 |
1971 |
[2] |
| IBM System/370 model 158-3 |
1 Dhrystone MIPS |
1.0 |
0.1 |
1972 |
|
| Intel 8080 |
500 kIPS at 2 MHz |
0.3 |
0.3 |
1974 |
|
| MOS Technology 6502 |
500 kIPS at 1 MHz |
0.5 |
0.5 |
1975 |
|
| VAX-11/780 |
500 kIPS at 5 MHz |
0.2 |
0.2 |
1977 |
|
| Motorola 68000 |
1 MIPS at 8 MHz |
0.1 |
0.1 |
1979 |
|
| Intel 286 |
2.66 MIPS at 12.5 MHz |
0.2 |
0.2 |
1982 |
[3] |
| Motorola 68020 |
4 MIPS at 20 MHz |
0.2 |
0.2 |
1984 |
|
| Intel 386DX |
11.4 MIPS at 33 MHz |
0.3 |
0.3 |
1985 |
|
| ARM2 |
4 MIPS at 8 MHz |
0.5 |
0.5 |
1986 |
|
| Motorola 68030 |
11 MIPS at 33 MHz |
0.3 |
0.3 |
1987 |
|
| Motorola 68040 |
44 MIPS at 40 MHz |
1.1 |
1.1 |
1990 |
[4] |
| DEC Alpha 21064 EV4 |
300 MIPS at 150 MHz |
2.0 |
2.0 |
1992 |
[5] |
| Intel 486DX |
54 MIPS at 66 MHz |
0.8 |
0.8 |
1992 |
|
| Motorola 68060 |
88 MIPS at 66 MHz |
1.33 |
1.33 |
1994 |
|
| Intel Pentium |
188 MIPS at 100 MHz |
1.88 |
1.88 |
1994 |
[6] |
| Microchip PIC16F |
5 MIPS at 20 MHz |
0.25 |
0.25 |
1995 |
[7] |
| Atmel megaAVR |
16 MIPS at 16 MHz |
1 |
1 |
1996 |
[8] |
| ARM 7500FE |
35.9 MIPS at 40 MHz |
0.9 |
0.9 |
1996 |
|
| Intel Pentium Pro |
541 MIPS at 200 MHz |
2.7 |
2.7 |
1996 |
[9] |
| PowerPC 750 |
525 MIPS at 233 MHz |
2.3 |
2.3 |
1997 |
|
| Zilog eZ80 |
80 MIPS at 50 MHz |
1.6 |
1.6 |
1999 |
[10] |
| Intel Pentium III |
2,054 MIPS at 600 MHz |
3.4 |
3.4 |
1999 |
[6] |
| Freescale MPC8272 |
760 MIPS at 400 MHz |
1.9 |
1.9 |
2000 |
[11] Integrated Communications Processors |
| AMD Athlon |
3,561 MIPS at 1.2 GHz |
3.0 |
3.0 |
2000 |
|
| AMD Athlon XP 2500+ |
7,527 MIPS at 1.83 GHz |
4.1 |
4.1 |
2003 |
[6] |
| Pentium 4 Extreme Edition |
9,726 MIPS at 3.2 GHz |
3.0 |
3.0 |
2003 |
|
| MIPS32 4KEc |
356 MIPS at 233 MHz |
1.5 |
1.5 |
2004 |
[12] |
| Microchip PIC10F |
1 MIPS at 4 MHz |
0.25 |
0.25 |
2004 |
[13][14] |
| ARM Cortex-M3 |
125 MIPS at 100MHz |
1.25 |
1.25 |
2004 |
[15] |
| Nios II/f |
190 MIPS at 165 MHz |
1.13 |
1.13 |
2004 |
[16] |
| ARM Cortex-A8 |
2,000 MIPS at 1.0 GHz |
2.0 |
2.0 |
2005 |
[17] |
| VIA C7 |
1,799 MIPS at 1.3 GHz |
1.4 |
1.4 |
2005 |
[18] |
| AMD Athlon FX-57 |
12,000 MIPS at 2.8 GHz |
4.3 |
4.3 |
2005 |
|
| AMD Athlon 64 3800+ X2 (Dual core) |
14,564 MIPS at 2.0 GHz |
7.3 |
3.6 |
2005 |
[19] |
| Xbox360 IBM "Xenon" (Triple core) |
19,200 MIPS at 3.2 GHz |
6.0 |
2.0 |
2005 |
|
| PS3 Cell BE (PPE only) |
10,240 MIPS at 3.2 GHz |
3.2 |
3.2 |
2006 |
|
| AMD Athlon FX-60 (Dual core) |
18,938 MIPS at 2.6 GHz |
7.3 |
3.6 |
2006 |
[19] |
| Intel Core 2 Extreme X6800 (Dual core) |
27,079 MIPS at 2.93 GHz |
9.2 |
4.6 |
2006 |
[19] |
| Intel Core 2 Extreme QX6700 (Quad core) |
49,161 MIPS at 2.66 GHz |
18.4 |
4.6 |
2006 |
[20] |
| MIPS32 24K |
604 MIPS at 400 MHz |
1.51 |
1.51 |
2006 |
[21] |
| ARM Cortex-R4 |
450 MIPS at 270 MHz |
1.66 |
1.66 |
2006 |
[22] |
| MIPS64 20Kc |
1,370 MIPS at 600 MHz |
2.3 |
2.3 |
2007 |
[23] |
| P.A. Semi PA6T-1682M |
3,084 MIPS at 1.8 GHz |
4.4 |
4.4 |
2007 |
[24] |
| Intel Core 2 Extreme QX9770 (Quad core) |
59,455 MIPS at 3.2 GHz |
18.6 |
4.6 |
2008 |
[25] |
| Intel Core i7 920 (Quad core) |
82,300 MIPS at 2.66 (Turbo 2.93) GHz |
30.9 |
7.7 |
2008 |
[26] |
| Intel Atom N270 (Single core) |
3,846 MIPS at 1.6 GHz |
2.4 |
1.2 |
2008 |
[27] |
| ARM Cortex-M0 |
45 MIPS at 50MHz |
0.9 |
0.9 |
2009 |
[28] |
| ARM Cortex-A9 (Dual core) |
5,000 MIPS at 1.0 GHz |
5.0 |
2.5 |
2009 |
[29] |
| AMD E-350 (Dual core) |
10,000 MIPS at 1.6 GHz |
6.25 |
3.125 |
2011 |
[30] |
| AMD Phenom II X4 940 Black Edition |
42,820 MIPS at 3.0 GHz |
14.3 |
3.5 |
2009 |
[31] |
| AMD Phenom II X6 1100T |
78,440 MIPS at 3.3 GHz |
23.7 |
3.9 |
2010 |
[26] |
| ARM Cortex-A15 (Quad core) |
35,000 MIPS at 2.5 GHz |
14.0 |
3.5 |
2010 |
[32] |
| Intel Core i7 Extreme Edition 980X (Hex core) |
147,600 MIPS at 3.33 GHz |
44.7 |
7.46 |
2010 |
[33] |
| Intel Core i7 2600K |
128,300 MIPS at 3.4 GHz |
37.7 |
9.43 |
2011 |
[34] |
| Intel Core i7 875K |
92,100 MIPS at 2.93 GHz |
31.4 |
7.85 |
2011 |
[35] |
| AMD FX-8150 (Eight core) |
108,890 MIPS at 3.6 GHz |
30.2 |
3.78 |
2011 |
[36] |
| ARM11 |
515 MIPS at 412 MHz |
1.25 |
1.25 |
2002 |
[37] |
| ARM Cortex A7 |
2,850 MIPS at 1.5 GHz |
1.9 |
1.9 |
2011 |
[38] |
| Qualcomm Scorpion (Cortex A8-like) |
2,100 MIPS at 1 GHz |
2.1 |
2.1 |
2008 |
[39] |
| Qualcomm Krait (Cortex A9-like, Dual core) |
9,900 MIPS at 1.5 GHz |
6.6 |
3.3 |
2011 |
[40] |
| Intel Core i7 Extreme Edition 3960X (Hex core) |
177,730 MIPS at 3.33 GHz |
53.3 |
8.89 |
2011 |
[41] |