I get a Perflib_Perfdata_xxx.dat file in my Temp folder but it's associated with my Retrospect Backup software and automatically deletes when I exit the application.
AFAIK, the dat file is not directly created by Retrospect Backup but is created by a Microsoft background process called the Performance Data Log Service utility triggered by the application. You can find numerous references in the Microsoft Knowledge Base.
You may have an application that also triggers the process.