Go to the "Devices" menu and select "Plug-in Information", this list will show you all of your installed plugins that are available to Cubase and their latency etc...
To constrain the latency (i.e. switch off all plugins that have a delay in their audio stream, click the clock icon about 3 icons from the left up the top on your Cubase control panel, if it's not there, right click in a blank part of this top icon panel section and select "Constrain Delay Compensation", this will show the icon of which you may now click
pitty i found this thread too late, i have an RME card for sale mega cheap... you won't regret buying an RME card, they are solid and the drivers are second to none.
Good luck!