我的驱动器上有一些扇区读数很差。 我可以衡量每个部门所需的阅读时间，然后比较好部门和坏部门的时间。
我可以使用处理器的计时器进行测量。 如何在C / Assembly中编写程序来衡量每个扇区读取的确切时间？
所以程序将是这样的：
Start the timer Read the disk sector Stop the timer Read the time measured by the timerI have some sectors on my drive with poor reading. I could measure the reading time required by each sector and then compare the time of the good sectors and the bad sectors.
I could use a timer of the processor to make the measurements. How do I write a program in C/Assembly that measures the exact time it takes for each sector to be read?
So the procedure would be something like this:
Start the timer Read the disk sector Stop the timer Read the time measured by the timer最满意答案
最有用的功能是“rdtsc”指令（ReaD时间戳计数器），每当处理器的内部时钟递增时，该指令就会递增。 对于3 Ghz处理器，它每秒增加30亿次。 它返回一个64位无符号整数，包含自处理器上电以来的时钟周期数。
显然，两个读出之间的差异是在中间执行代码序列所消耗的时钟周期数。 对于3 Ghz机器，您可以使用以下任何算法转换为秒的部分：
（time_difference + 150）/ 300以0.1 us（十分之一微秒）给出舍入的经过时间（time_difference + 1500）/ 3000给出了我们的舍入经过时间（微秒）（time_difference + 1500000/3000000给出四舍五入的经过时间）以毫秒为单位的时间（毫秒）
0.1 us算法是您可以使用的最精确的值，无需调整读出开销。
The most useful functionality is the "rdtsc" instruction (ReaD Time Stamp Counter) which is incremented every time the processor's internal clock increments. For a 3 Ghz processor it increments 3 billion times per second. It returns a 64 bit unsigned integer containing the number of clock cycles since the processor was powered on.
Obviously the difference between two read-outs is the number of elapsed clock cycles consumed for executing the code sequence in-between. For a 3 Ghz machine you could use any of the following algorithms to convert to parts of seconds:
(time_difference+150)/300 gives a rounded off elapsed time in 0.1 us (tenths of microseconds) (time_difference+1500)/3000 gives a rounded off elapsed time in us (microseconds) (time_difference+1500000/3000000 gives a rounded off elapsed time in ms (milliseconds)
The 0.1 us algorithm is the most precise value you can use without having to adjust for read-out overhead.
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