Question:

Is there an option to use Single Precision on a Sparse Solver?

Answer:

There is no single precision sparse solver. Also, WE RECOMMEND AGAINST USING THE SINGLE PRECISION PCG SOLVER, EVEN THOUGH IT IS DOCUMENTED. The single precision PCG solver was implemented in the early days of iterative solvers to permit the user to solve large problems without the required memory. The single precision PCG solver stores real numbers as REAL*4 instead of REAL*8 (or Double Precision). Use of the single precision PCG solver can lead to significant round off error which may result in incorrect answers. The question we would ask is "Do you want good answers or will any answer do?" If any answer will do, use the single precision PCG solver. Double precision is the rule in ANSYS and all internal real variables in the ANSYS program are Double Precision. Today, computational horsepower is cheap and users should invest in what is required to solve their problem.


Question:

Is there an option to use Single Precision on a Sparse Solver?

Answer:

There is no single precision sparse solver. Also, WE RECOMMEND AGAINST USING THE SINGLE PRECISION PCG SOLVER, EVEN THOUGH IT IS DOCUMENTED. The single precision PCG solver was implemented in the early days of iterative solvers to permit the user to solve large problems without the required memory. The single precision PCG solver stores real numbers as REAL*4 instead of REAL*8 (or Double Precision). Use of the single precision PCG solver can lead to significant round off error which may result in incorrect answers. The question we would ask is "Do you want good answers or will any answer do?" If any answer will do, use the single precision PCG solver. Double precision is the rule in ANSYS and all internal real variables in the ANSYS program are Double Precision. Today, computational horsepower is cheap and users should invest in what is required to solve their problem.





Show Form
No comments yet. Be the first to add a comment!