I have never used GPU for puzzle searching.
Only keyhunt, I like it and I enjoy playing with the "spaces".
Question... with a GPU system is it possible to search for multiple public addresses together or just one?
do software that use GPU accept a .txt file like the one generated by keysubtracter?
Yes, I did multiple with Bitcrack but there is a bug in the code that causes an error if you use more than 15 addresses in your text file. There is a proposed solution to the bug that has to be fixed before building and maybe that will work for more than 15 but I haven't tried.