Hi Joe,
difficult to say the reason, could be hardware or software reasons. Are you sure that Prod and Dev have servers with the same hardware, normally Dev is a weaker server and maybe the SQL or IIS doesn't have the optimal settings.
However I don't think the reason is the difference from sp5 to sp11.
In the installation guide there are the HW prerequisites, you should verify if also DEV have these characteristics or not and also if ok it there are different hardware in PROD. IF there are identical then you should check IIS and SQL settings.
Regards
Roberto