No, UltraFinder does not collect data of certain file types in background in a large database like Google Desktop or Microsoft Desktop do. As such an index based search is already built-in in Vista, Windows 7 and Windows 8, it does not make sense to have a second application running in background using a lot of RAM, disk space and also CPU time to build another search index database. For Windows XP a free index based desktop search application can be installed if that is what you want.
UltraFinder really searches on the fly in the files you specify and in the directory tree selected before starting the find. Of course if you start your search in root on drive C: and do not limit the search to certain file types, it can take some minutes until UltraFinder has searched in all the thousands of files of drive C: the entered string. Well, a second find with a different search string in same files will be much quicker as Windows has now on second run the files already cached in RAM and therefore UltraFinder is much quicker as Windows does not need to load the data again from disk into RAM.
An index based search for simple strings is in the scenario you described much faster mainly because the index does not take all files on computer into account. Open the preferences dialog of Google or Microsoft Desktop search and you will see on which files and directories those index based search are really working on.
UltraFinder is not designed as yet another index based search tool. It is designed for offering features which Windows built-in search does not offer like multi-line string search, or a regular expression search, or finding duplicate files, etc. If you are looking for an index based search tool, UltraFinder is not a tool for you.