I'm not sure if Interworks is creating Performance Analyzer for v8, you might want to check their blog or website and ask them.
There is an easy workaround to your problem in v8, however.
- Add a new data source to your workbook which contains maybe 1 column and a single row of data.
- Create a worksheet based on that worksheet
- Drag the worksheet to the front of your list of worksheets.
- Save and close.
When you open the workbook the "dummy" worksheet will render using a data source you don't care about. Turn on performance recording and then select the worksheet and/or dashboard you really want to measure. The report which comes back will show the behavior of the dashboard in question when it is rendered "cold".
Hope this helps!
Thanks Russell for your suggestion..