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] |
