Are you looking to load a single 5GB file into a single table?

There are a variety of ways to do this. Is there a transform? Is it a straight load? Bulk insert is about the fastest way to do this. You can also use SSIS, and there is a paper on high performance loads here:

https://technet.microsoft.com/en-us/library/dd537533%28v=sql.100%29.aspx

Need a bit more detail.