Calculating power

1. 1、 Lever
(1) basic concept of lever
a hard rod that can rotate around a fixed point under the action of force is called lever
there are five terms of lever: ① fulcrum: the point around which the lever rotates (o); ② Power: the force that makes the lever rotate (F1); ③ Resistance: the force that prevents the rotation of the lever (F2); ④ Power arm: distance from fulcrum to action line of power (L1); ⑤ Resistance arm: distance from fulcrum to resistance action line (L2)< (2) the condition of leverage balance × Power arm = resistance × The resistance arm, the equilibrium condition, is the lever principle discovered by Archimedes< (3) three levers:
1. Labor saving lever: L1 & gt; L2, F1 & lt; F2 The feature is labor saving, but it costs a lot of distance (e.g. iron scissors, guillotine, driver)
② lever: L1 & lt; L2, F1 & gt; F2 The characteristic is laborious, but saves the distance (e.g. fishing rod, barber scissors, etc.)
③ equal arm lever: L1 = L2, F1 = F2 when balancing. It is characterized by no effort and no effort Such as: balance)
2. Buoyancy
(1) buoyancy
the upward force of liquid or gas on an object immersed in liquid or gas is called buoyancy. The cause of buoyancy is: the object immersed in liquid (or gas) is subject to the upward and downward pressure difference of liquid (or gas). Buoyancy is applied to liquid (or gas), buoyancy belongs to elastic force
(2) Archimedes principle
an object immersed in liquid is subject to upward buoyancy, which is equal to the gravity of the liquid it displaces. Expression: F = g row= ρ Liquid V discharges g (Archimedes principle also applies to gas)
it can be concluded that the density of the liquid and the volume of the liquid displaced by the object are two factors that affect the buoyancy< (3) the calculation method of buoyancy
① Archimedes principle: F floating = g row= ρ Liquid V row g (also suitable for gas)
② two force balance: F floating = g object (suitable for floating and suspension)
③ multi force balance: F floating = G-F (this is the case of measuring buoyancy with a spring dynamometer)
④ pressure difference method: F floating = f up-f down (not commonly used)
(4) measurement of buoyancy
① common method: measure the gravity g of an object with a spring dynamometer, When an object is immersed in the liquid and the indication F of the spring dynamometer is read out, the buoyancy of the object immersed in the liquid is: F floating = G-F< (2) measuring v-row (measuring cylinder) method: measure v-row and use f = g-row= ρ The buoyancy of liquid V row G is calculated
(5) the buoyancy and sinking conditions of objects are determined by the relationship between gravity and buoyancy. ① When gravity is greater than buoyancy, the object sinks; ② When gravity equals buoyancy, the object floats; ③ When gravity is less than buoyancy, the object floats< (6) utilization of buoyancy
1. Ship: hollow method is used to increase the available buoyancy, so that the ship can float on the water. The size of a ship is expressed in terms of its displacement - the mass of boiled water discharged when it is fully loaded
② submarine: submarine floats and sinks by changing its own gravity
③ balloons and airships: both use the buoyancy of the air to work. Balloon and airship lift, mainly by changing the volume of the airbag to change their own buoyancy to achieve.

2. I think if we only know volume and velocity, we can't find the force. i 'm sorry!

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4. < UL >

the system is unstable e to high temperature. Please check if there is any problem in the heat dissipation of CPU, graphics card, memory, hard disk, motherboard, etc. When checking the above components, check whether there is a problem of false soldering of electronic components or circuits, which makes the system unstable at high temperature, and confirm again whether it is a problem of display or power supply

graphics card driver, the computer has a common feature when running software, that is, the screen resolution will be switched, if you use 1024 × 768 resolution, when running some large software, it is easy to switch to a lower resolution. If there is a problem with the driver of the graphics card, it is likely that there will be a failure when switching the resolution, resulting in the computer black screen. The problem can be solved after updating the driver of the graphics card

the version of DirectX is too low. If the version of DirectX is too low, the problem of black screen can be solved by installing the graphics card driver and the latest version of DirectX program

5. computing power is a concept put forward by NVIDIA when it released CUDA (Compute Unified Device Architecture, a programming language for GPU, similar to C programming for CPU). Because the graphics card itself is a floating-point computing chip, it can be used as a computing card, so the graphics card has computing power. Different graphics cards have different computing power. In order to show the difference, NVIDIA put forward the corresponding version of computing power x.x on the procts of different periods. Computing power 1.0 appeared on early graphics cards, such as the original 8800 ultra and many 8000 Series cards, as well as Tesla C / D / s870s cards. Cuda1.0 was released corresponding to these graphics cards. Today, computing power 1.0 has been eliminated from the market. Then there was computing power 1.1, which appeared on many 9000 Series graphics cards. Computing power 1.2 appears together with GT200 Series graphics card, while computing power 1.3 is proposed when upgrading from GT200 to GT200 A / b revision. In the future, there will be computing power 2.0, 2.1, 3.0 and other versions. The latest released version is computing power 6.1, which is supported by the latest Pascal architecture graphics card. At the same time, CUDA version is also updated to cuda8.0

ordinary users do not need to care about the computing power of the graphics card, only GPU programmers care about this problem when they write CUDA programs to develop GPU computing. As long as you know the model of your computer's graphics card, you can find the corresponding computing power https://developer.nvidia.com/cuda-gpus .

6. The gt610m is actually an overclocking version of the gt520m. It is an entry-level graphics card and low-end
number of shaders: 48unified
manufacturing process: 40nm
grating unit: 4
bit width: 64bit
capacity: 2048m
computing power:
pixel fill rate: 1.7gpixel/s
texture fill rate: 6.8gtexel/s
video memory bandwidth: 12.8gb
hope to help you.

7. 1. Giga, abbreviated as G, is the prefix of quantity, which means 10 ^ 9, that is, 1 billion. For example, 9g is 9 billion., 2, the unit of floating-point computing power is flops (i.e. "floating point operations per second", "peak speed per second"), not "float". Short for floating-point operations per second. It is often used to estimate the performance of computer, especially in the field of scientific computing which uses a large number of floating-point operations. Because the s at the end of flops stands for seconds, not plurals, so it can't be omitted
the so-called "floating-point operation" here actually includes all operations involving decimals. This kind of operation often appears in some kind of application software, and they also take more time than integer operation. Most of today's processors have a special "floating point unit" (FPU) for processing floating-point operations. Therefore, what flops measures is actually the execution speed of FPU. Linpack is one of the most commonly used benchmarks to measure flops
3. Gigaflops is one billion floating-point operations per second, which is also the unit to describe the floating-point computing capacity of computers. The mainstream CPU is generally between 20-60 gflops.

8.

It includes CUDA instruction set architecture (ISA) and parallel computing engine in GPU. Developers can now use C language to support CUDA; Architecture programming, C language is the most widely used high-level programming language. The program can then support CUDA & 8482; Runs at ultra-high performance on the processor. Other languages, including FORTRAN and C + +, will be supported in the future

with the development of graphics card, GPU becomes more and more powerful, and GPU optimizes the display image. It has surpassed the general CPU in computing. If such a powerful chip is only used as a graphics card, it would be too wasteful. Therefore, NVIDIA launched CUDA, which enables the graphics card to be used for purposes other than image computing

At present, only NVIDIA graphics cards on g80, G92, G94 and GT200 platforms can use CUDA, and the core of the toolkit is a C language compiler. G80 has 128 separate ALUs, so it is very suitable for parallel computing, and the speed of numerical calculation is much faster than CPU

The compiler and development platform in CUDA SDK support windows and Linux systems, and can be integrated with Visual Studio 2005

at present, this technology is in its infancy, which only supports 32-bit system, and the compiler does not support double precision data, which will be solved later. Geforce8cuda (Compute Unified Device Architecture) is a new infrastructure, which can use GPU to solve complex computing problems in business, instry and science. It is a complete GPGPU solution, which provides direct access interface to hardware instead of relying on graphical API interface to achieve GPU access

in the architecture, a new computing architecture is adopted to use the hardware resources provided by GPU, which provides a more powerful computing power than CPU for large-scale data computing applications. CUDA uses C language as programming language to provide a large number of high-performance computing instruction development capabilities, which enables developers to build a more efficient data intensive computing solution based on the powerful computing power of GPU< br />

9. Excel is more than 60000 lines at most, but more than 100000 lines have no response. Let's take an i7 and spend 6000 with a better one

10. Floating point operation when we use different computers to calculate pi, we will find that one computer's calculation is more accurate than the other. Xu Ruti or when we are in a gun fight, when a bullet hits the wall, a piece of the wall will peel off. The same scene on a computer may be very rigid and artificial; And on another computer, it will be very vivid, even close to what we see in reality. This is caused by the difference of floating-point computing ability. Floating point operation is real number operation, because computers can only store integers, so real numbers are divisors, so floating-point operation is very slow and there will be errors
now most machines are 32-bit, that is to say, 32 is used to represent integers, then for unsigned integers it is 0 to 2 ^ 32-1, for signed integers it is - 2 ^ 31 to 2 ^ 31-1. If it's a real number, it's not like this. The machine has two ways to represent real numbers. One is fixed point, that is, the decimal point position is fixed. The other is floating point, that is, the decimal point position is not fixed. The calculation method is troublesome, and it usually costs a lot more FPU - & gt; than integer operation; Floating point unit
BCD - & gt; Binary coded decimal compressed decimal numbers use four bits to represent numbers 0 ~ 9, and a byte to represent two decimal numbers. For example, 01111001 represents 89
scientific counting method: This is scientific ~ ~ ~ for specific meaning, check junior high school or primary school mathematics textbook D:)
floating point operation uses three different kinds of data:
1) integer, which is also divided into words, Short integer and long integer
2) real (single real) and double real (double real)
3) compressed decimal number (BCD)
the following is the number of bits and the approximate range that can be expressed and
type length range
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Eger 32 bit - 2.14e9 to 2.14e9
long integer 64 bit - 9.22e18 to 9.22e18
single real 32 bit 1.18e-38 to 3.40e38
double real 64 bit 2.23e-308 to 1.79e308
extended real 80 bit 3.37e-1932 to 1.18e4932
packed BCD 80 bit - 1e18 to 1e18
the expression range of double precision number and extended precision number is large enough for general application
1) integers are stored in the form of complements. The complements of positive numbers are themselves, while the complements of negative numbers are their absolute values, The following is an example of actual storage:
0024 VAR1 DW 24
fffe var2 DW - 2
000004d2 var3 DD 1234
ffffff85 VAR4 DD - 123
000000 2694var5 DQ 9876
2) BCD number
in FPU, 80 bits is exactly the width of floating-point heap register, and the storage format is as follows:
bit
79___ 72_ 71________________________________________ 0
symbol --- 18 decimal numbers ------
look at the following example:
10000000000012345 VAR1 DT 12345
800000000000100 var2 DT - 100
3) floating point, this complex point has three formats
single precision:_ 31_ 30________ 23_ 22___________ 0
sign exponent significant number
double precision:_ 63_ 62__________ 52_ 51__________________ 0
significant number of sign index
extended precision number:
_ 79_ 78____________ 64_ 63___________________ 0
sign index significant number
examples:
c377999a VAR1 DD - 247.6
4000000 var2 DD 2.0
486f4200 var3 real4 2.45e + 5
40591000000 VAR4 DQ 100.25
3f543bf727136a40 var5 real8 0.00123
c377999a VAR1 DD - 247.6
4000000 var2 DD 2.0
486f4200 var3 real4 2.45e + 5
405910000000000 VAR4 DQ 100.25
3f543bf72 7136a40 var5 real8 0.001235
400487f34d6a161e4f76 VAR6 real10
in addition, the common form of floating-point operation is square root operation.