First make sure that you have installed the last IDU 1.2.5 from CCO for DFM 1.2 to avoid running into any similar old bugs. To change the threshld, launch DFM Admin Console, Edit->Polling and Thresholds, select the Threhold tab, select the System Resource Group->Switches->Processor and Memory. Change the value to your choice and click on Apply to save the changes.