Here is a link to an older topic that discusses the CPU time expected with TurbSim simulations: TurbSim CPU Times. Keep in mind that I was using a slower computer 12 years ago. 
The relationship between the number of grid points and the CPU time should hold, but the actual times will vary. Also, if your simulation requires more memory than your computer has available, your CPU times will suffer. You can calculate the approximate memory requirements here: Memory Requirements for full-field wind arrays
@Salur.Basbug: I do not see any reason for you to use a double-precision version of TurbSim. The wind speeds that are generated have random phases and are ultimately truncated to about 3 decimal places of precision, so computing the velocities in double-precision will slow down the process and use more memory without creating any more accuracy.
A 64-bit version of TurbSim will allow you to compute larger grids (i.e., use more memory) than a 32-bit version, but this is different than using double-precision vs single-precision arithmetic. (Note: Iām making this distinction here because many people get the addressing scheme and precision of arithmetic confused.) If you are using the Windows version distributed with the latest OpenFAST release, that is a 64-bit single-precision arithmetic version.