Description: 一．高精度延时, 是 CPU 测速的基础
Windows 内部有一个精度非常高的定时器, 精度在微秒级, 但不同的系统这个定时器的频率不同, 这个频率与硬件和操作系统都可能有关。
利用 API 函数 QueryPerformanceFrequency 可以得到这个定时器的频率。
利用 API 函数 QueryPerformanceCounter 可以得到定时器的当前值。
根据要延时的时间和定时器的频率, 可以算出要延时的时间定时器经过的周期数。
在循环里用 QueryPerformanceCounter 不停的读出定时器值, 一直到经过了指定周期数再结束循环, 就达到了高精度延时的目的。
高精度延时的程序, 参数: 微秒
二．测速程序
利用 rdtsc 汇编指令可以得到 CPU 内部定时器的值, 每经过一个 CPU 周期, 这个定时器就加一。
如果在一段时间内数得 CPU 的周期数, CPU工作频率 = 周期数 / 时间
为了不让其他进程和线程打扰, 必需要设置最高的优先级
以下函数设置当前进程和线程到最高的优先级。
SetPriorityClass(GetCurrentProcess(), REALTIME_PRIORITY_CLASS)
SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL)
CPU 测速程序的源代码, 这个程序通过 CPU 在 1/16 秒的时间内经过的周期数计算出工作频率, 单位 MHz:
-one. High-precision delay, the CPU speed is the basis of Windows within a very high accuracy of the timer, the microsecond precision, but in the system timer different frequencies, the frequency and hardware and the operating system are likely. Using API function can be QueryPerformanceFrequency the timing The frequency. Use QueryPerformanceCounter API function can be the current timer value. According to the delay time and the frequency of the timer, you could calculate the time to delay timer after a few cycles. The circle with QueryPerformanceCounter repeatedly read out the timer value, until after a specified number of cycles end the cycle again, it reached a high precision delay purposes. High-precision delay the procedure parameters : 2 microsecond. Gun utilize RDTSC instruction can Platform: |
Size: 1213 |
Author:马俊 |
Hits:
Description: 这个频率与硬件和操作系统都可能有关。利用 API 函数 QueryPerformanceFrequency 可以得到
这个定时器的频率。利用 API 函数 QueryPerformanceCounter 可以得到定时器的当前值。根据
要延时的时间和定时器的频率, 可以算出要延时的时间定时器经过的周期数。在循环里用
QueryPerformanceCounter 不停的读出定时器值, 一直到经过了指定周期数再结束循环, 就达到-the frequency with hardware and the operating system are likely. Using API function can be QueryPerformanceFrequency the timing The frequency. QueryPerformanceCounter API function can be present timer value. According to the delay time and the frequency of the timer, you could calculate the time to delay timer after a few cycles. In the circle with QueryPerformanceCounter kept read timer value, until after a specified number of cycles end the cycle again, to achieve Platform: |
Size: 238447 |
Author:xianhao |
Hits:
Description: 一．高精度延时, 是 CPU 测速的基础
Windows 内部有一个精度非常高的定时器, 精度在微秒级, 但不同的系统这个定时器的频率不同, 这个频率与硬件和操作系统都可能有关。
利用 API 函数 QueryPerformanceFrequency 可以得到这个定时器的频率。
利用 API 函数 QueryPerformanceCounter 可以得到定时器的当前值。
根据要延时的时间和定时器的频率, 可以算出要延时的时间定时器经过的周期数。
在循环里用 QueryPerformanceCounter 不停的读出定时器值, 一直到经过了指定周期数再结束循环, 就达到了高精度延时的目的。
高精度延时的程序, 参数: 微秒
二．测速程序
利用 rdtsc 汇编指令可以得到 CPU 内部定时器的值, 每经过一个 CPU 周期, 这个定时器就加一。
如果在一段时间内数得 CPU 的周期数, CPU工作频率 = 周期数 / 时间
为了不让其他进程和线程打扰, 必需要设置最高的优先级
以下函数设置当前进程和线程到最高的优先级。
SetPriorityClass(GetCurrentProcess(), REALTIME_PRIORITY_CLASS)
SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL)
CPU 测速程序的源代码, 这个程序通过 CPU 在 1/16 秒的时间内经过的周期数计算出工作频率, 单位 MHz:
-one. High-precision delay, the CPU speed is the basis of Windows within a very high accuracy of the timer, the microsecond precision, but in the system timer different frequencies, the frequency and hardware and the operating system are likely. Using API function can be QueryPerformanceFrequency the timing The frequency. Use QueryPerformanceCounter API function can be the current timer value. According to the delay time and the frequency of the timer, you could calculate the time to delay timer after a few cycles. The circle with QueryPerformanceCounter repeatedly read out the timer value, until after a specified number of cycles end the cycle again, it reached a high precision delay purposes. High-precision delay the procedure parameters : 2 microsecond. Gun utilize RDTSC instruction can Platform: |
Size: 1024 |
Author:马俊 |
Hits:
Description: 这个频率与硬件和操作系统都可能有关。利用 API 函数 QueryPerformanceFrequency 可以得到
这个定时器的频率。利用 API 函数 QueryPerformanceCounter 可以得到定时器的当前值。根据
要延时的时间和定时器的频率, 可以算出要延时的时间定时器经过的周期数。在循环里用
QueryPerformanceCounter 不停的读出定时器值, 一直到经过了指定周期数再结束循环, 就达到-the frequency with hardware and the operating system are likely. Using API function can be QueryPerformanceFrequency the timing The frequency. QueryPerformanceCounter API function can be present timer value. According to the delay time and the frequency of the timer, you could calculate the time to delay timer after a few cycles. In the circle with QueryPerformanceCounter kept read timer value, until after a specified number of cycles end the cycle again, to achieve Platform: |
Size: 238592 |
Author:xianhao |
Hits:
Description: collection of awk script use to measure and calculate end-to-end delay, average delay, jitter, throughput-collection of awk script use to measure and calculate end-to-end delay, average delay, jitter, throughput.. Platform: |
Size: 6144 |
Author:ismail |
Hits:
Description: 延时渲染，首先准备N个与屏幕同大小的纹理作为渲染缓冲区，接下来向这个纹理渲染东西，一般用FBO，渲染的时候，把每个象素最终的法线值、位置、纹理信息分别渲染到这N个纹理中。这是第一次渲染。然后第二次渲染的时候，把之前得到的纹理中的值作为光照计算的输入值来计算光照。-Delay rendering, the first screen for N-and render the same size as a buffer texture, the next thing to render the texture, the general use of FBO, render time, the normal end of each pixel value, position, texture information N, respectively, rendering a texture to this. This is the first rendering. Then, when the second rendering, the texture before the value obtained by calculating the input value as a light to calculate the light. Platform: |
Size: 396288 |
Author:wz |
Hits:
Description: this a source for implementation of
a sample network with opnet v14.5
with c++ code for statistical distribution and
calculate of end to end delay in sample network-this is a source for implementation of
a sample network with opnet v14.5
with c++ code for statistical distribution and
calculate of end to end delay in sample network Platform: |
Size: 4681728 |
Author:yavar |
Hits:
Search - end to end delay calculate