Get time in microsecond in delphi language [duplicate]

There is a CPU-dependent "high resolution performance counter" that you can access with the QueryPerformanceCounter() API call.

QueryPerformanceCounter() gives you the value of that performance counter. (Historically, the performance counter was simply a count of CPU cycles, but hyper-threading and multi-core CPUs have made that unreliable, so now it just measures some very small interval of time, < 1us)

To find out what this unit of time is, use QueryPerformanceFrequency(). This gives you the number of high-resolution performance counter units per second. To get the number per microsecond, divide by 1000000. On my Sandy Bridge i7, it's about 35 units per microsecond.

Some code:

Using QueryPerformanceCounter to measure the execution time of some code:

var
  StartTime, EndTime, Delta: Int64;
begin
  QueryPerformanceCounter(StartTime);
  //Code you want to measure here
  QueryPerformanceCounter(EndTime);
  Delta := EndTime - StartTime;
  //Show Delta so you know the elapsed time
end;

Using QueryPerformanceFrequency to find out how many high-resolution units are in a microsecond:

var
  Frequency, UnitsPerMS: Int64;
begin
  QueryPerformanceFrequency(Frequency);
  UnitsPerMS := Frequency div 1000000;
end;