Looks like you've got the obvious...

Increase your sort_area_size temporarily.

Here's a long shot .. are you creating datafiles or autogrowing in 8.0.x? Those took FOREVER with UTF8 character set.

If you're spitting the results out to a log file, you might want to watch the file on your screen with a cool little utility for windows called tail. http://rhazes.com It works like "tail -f" in unix. As lines are added to the output file, they're also displayed on your console.

Best of Luck,

-Ken