# Pure ASP.NET file upload...I have my doubts...

<datetime class="hidden">2004-03-16T00:00</datetime>
<!-- category -- mostlylucidcouk, Imported, ASP.NET, Performance -->

OK, maybe someone 'in the know' can settle this, is it possible to upload large files efficiently purely using ASP.NET? 
I've been [following a thread](http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&amp;PostID=55127)in the [ASP.NET forums](http://www.asp.net/Forums) about providing a method to do this using HttpHandlers / Modules to do this. What confuses me though is, is there any point to this? As I understand it, IIS will cache a Request stream before passing it, in it's entirety, to ASP.NET. If this is true then there's no way to efficiently upload files in ASP.NET - since the whole file would need to be held in memory before upload - uploading a 4GB file would require 4GB+ of memory. Can anyone confirm this, does IIS 6.0 change this behaviour???