Page RegisterAsyncTask server strange behavior

Current context: We have a web page that requires multiple lists to be loaded in parallel, and we decided to do this with page.RegisterAsyncTask (as soon as we do that, we call the .ExecuteRegisteredAsyncTasks () page, the methods just load the data to be displayed as JSON on rendering, and on the page the Async attribute is set to true - so everything should be fine) On our dev machines (win 7 and win 8), performance improves significantly from 3 seconds to less than 1 second.

Problem: After deploying to staging / live server (Windows 2008 R2), there is no performance improvement over standard non-Async version.

Other solutions have tried: We tried loading tasks with Task.Factory.StartNew + Task.WaitAll in the Load page for individual threads and the same behavior as on intermediate dev machines. Tried changing the settings in the machine.config file on the staging server (although the restart is not complete yet) ()

Questions: Has anyone encountered this problem and if you could find a solution? This is caused by various thread scheduling algorithms from Win7 / 8 and Windows 2008 R2