I've been cleaning up one of the subsystems in our product (that I did not write) and it is now substantially faster than it was. Aside from the earlier improvements I made in it, I taught it to cache two values that my version of this particular subsystem has cached since it was written. Doing this took the execution time to retrieve and write to a text stream a grid of nearly 700,000 cells from about 35 seconds down to 19 seconds.

There's other code that's running that is still taking way too long too execute, but this particular subsystem is now running much better.