Search:

I think the problem right now is, you have not provided enough for anyone to tell what the problem(s) is/are. We are making guesses and suggestions based on our understanding of what might be.

Agreed. But if I can cut my processing time to 1/4, I would likely make it a part of the solution.
Only the SSCCE and time will tell~

If you process them one at a time, you are restricted to linear time in processing. The-Time-To-Process-One-Item multiplied by The-Number-Of-Items
If the problem is a large number of items, then the...

Process on multiple threads