Input and Output

HPF currently has no provision for parallel I/O. In general, one processor performs all I/O so PRINT and READ statements are very expensive.

Upon encountering PRINT*, A(:,:)

• each processor must send its part of A to the I/O processor
• the I/O processor must service messages from every processor in turn
• rebuild the array
• and print out

this could be a lengthy process!

For more information, click here