但在实际上，要测量这些时间和距离，达到所需要的检测到纳秒级别差异的准确度，绝非易事。

But actually measuring those times and distances to the accuracy needed to detect nanosecond differences is no easy task.

youdao

要真正有效地使用它，需要对时间是如何测量的多少有一些了解。

To really apply it effectively is going to require some understanding of how time is being measured.

youdao

因为您不知道编译器什么时候执行，也不知道要执行多长时间，所以您可以看到，您的测量可能受到严重的歪曲。

Because you don't know when the compiler will run or for how long, you can see how your measurements could be badly distorted.

youdao