What causes the generation of the Overview Report (OVR) to take a long time?
The low performance for the generation of these two reports (OVR, Baseline Report) is caused by the conversion of an XML file into HTML. The generation time is dependant on Microsoft"s XML/XSL processor (msxml.dll), it is beyond our control to change this file.
A workaround is to turn off the automatic generation of the Overview Reports in Performance Explorer:
SETTINGS | OPTIONS | REPORTING TAB | GENERATE OVERVIEW REPORTS AUTOMATICALLY
Generation of the report can then be done manually only when really required. Manual generation is possible via the following method:
FILE | NEW | OVERVIEW REPORT
Select TSD file | Select Overview Template (if required) | Finish
It should also be noted that having multiple custom timers may impact the time it takes to generate a report due to the additional data that must be processed. In many cases custom timers are not needed as they are measuring, for example page download times which already have their own timer specified. If you have multiple custom timers please remove these and check if this makes any difference.