从SQL返回200mb blob需要多长时间

I have SQL 2008 R2 supporting a SharePoint 2010 environment. Some of the files will be stupidly large (i.e. 200mb). While Remote Blob Storage will be added to our platform in the future, I want to understand what reasonable performance might look like in getting a 200mb file to the user. I have SQL 2008 R2 supporting a SharePoint 2010