You are running a 32 bit app on a 64 bit operating system. You will take a hit as all 32 bit calls are thunked out to 64 bit words for execution.
Please read the release notes regarding recording in 64 bit environments.
There are a handful of things you can do to speed up replay execution. Since you have not specified how and why VUGEN is slow I am assuming you mean upon replay.
(1) Turn off animated replay
(2) Turn off runtime browser (if enabled)
(3) Reduce your logging level
(4) In your run time settings, set an extended attribute for "sensitivity" with a value of either 0 or 9. Either will be faster than vugen default.
(5) Record in a lower mode (which requires less CPU and memory). I.E., If you are in HTML mode, switch to URL mode.
There are some other items to be done, but keep in mind that you do take a hit for running a Win32 apop in a Win64 environment. If you want the best performance you need to take advantage of the native Win32 environment.
If it is not upon replay that you are experiencing the slowness then please clarify.
I fully agree, JVTKD. Vugen is incredibly slow in version 11.50, and this new version has other problems as well.
Evaluation of Loadrunner 11.50 at one client led to us sticking with 11.0 Patch 4 there. At another client, looking to upgrade from Performance Center 9.5, we decided to go to the equivalent 11.0 patch level (not going to version 11.50). We had received licenses for 11.50, but converting them to 11.0 was only a phone call to HP away (they did this very swiftly, thankfully).