That's a lot of data. Is there any way you can filter some of that data upfront?

You could run the SQL statement in the Initial SQL.  Once the filters have been created, right click on them and click on Applies to Worksheets and associate it with all sheets or just those you want.  As Ken stated, this is a huge lot of data.  You need to be sure you are only bringing in the fields and records that you need.  If there are multiple groups that will be using this data for different reasons, you might consider creating a custom sql statement for each of them and creating a separate dashboard for each group.  Getting the data in is only the first part of the problem.  How are your users going to view this information, will they have enough memory or patience to wait for the load?