Search & replace speed in Notepad++ / indexing

Question

I am using Notepad++ to search and replace in around 60, 000 files, one folder. It only seems to be processing around 2 files per second, is there any way to speed this up?

I have an i7 processor and 8gb ram. The search and replace is only 1 line of regex, and the files range from 20-500k html.

I have indexed the location on the hard drive but that hasn't seemed to help. The regex is:

Find

^.+?DataType4500" decimals="0" unitRef="Type5" name="uk-datefield-type3.+?sign="1.+?>(.+?)</(.+?)ion.*$

Replace

~\1

I'm doing other regexes, slightly different, all go at the same speed (running one at a time). I can open 5 instances and run them all at the same time, and all 5 Windows go at the same rate 1-2 files a second looking at the progress bar filename changes.