DateTime.Now多久更新一次？或者是否有更准确的API来获取当前时间？

I have code running in a loop and it's saving state based on the current time. Sometimes this can be just milliseconds apart, but for some reason it seems that DateTime.Now will always return values of at least 10 ms apart even if it's only 2 or 3 ms later. This presents a major problem since the state i'm saving depends on the time it was saved (e.g. recording something)I have code running in a loop and it's saving s